REM B LVL 1

Question 1

What is the science that describes and predicts the effect on bodies at rest or in motion by forces acting on it?

A. Engineering Mechanics
B. Mechanics of Materials
C. Theory of Structures
D. Strength of Materials

Answer 1

A. Engineering Mechanics
Engineering mechanics is a discipline devoted to the solution of engineering and mechanics problems through
integrated application of mathematical,
scientific, and engineering principles.
Special emphasis is placed on the
physical principles underlying modern
engineering design.

Question 2

Two objects move toward each other,
collide, and separate. If there was no net external force acting on the objects, but some kinetic energy was lost, then

A. the collision was not elastic and total
linear momentum was conserved
B. the collision was elastic and total linear
momentum was conserved
C. the collision was elastic and total linear
momentum was not conserved
D. the collision was not elastic and total
linear momentum was not conserved

Answer 2

A. the collision was not elastic and total
linear momentum was conserved

Question 3

Two objects, P and Q, have the same
momentum. Q has more kinetic energy
than P if it:

A. is moving slower than P
B. is moving faster than P
C. weighs the same as P
D. weighs more than P

Answer 3

B. is moving faster than P

Question 4

For a body to be in equilibrium under the
combined action of several forces:

A. any two of these forces must be balanced
by a third force
B. the sum of the components of all the
forces in any direction must equal zero
C. all of the forces form pairs of equal and
opposite forces
D. all the forces must be applied at the same
point

Answer 4

B. the sum of the components of all the
forces in any direction must equal zero

Question 5

It is the ratio of the distance through
which the input force acts to the
distance through which the output
forces acts.

A. Absolute Mechanical Advantage
B. Actual Mechanical Advantage
C. Natural Mechanical Advantage
D. Ideal Mechanical Advantage

Answer 5

D. Ideal Mechanical Advantage

Question 6

One joule of work is needed to move
one coulomb of charge from one point to another with no change in velocity.Which of the following is true between the two points?

A. The resistance is one ohm
B. The electric field strength is one newton
C. The current is one ampere
D. The potential difference is one volt

Answer 6

D. The potential difference is one volt

A potential of one volt has the capacity to do one joule of work in moving one coulomb of charge.

Question 7

Which of the following groups does NOT
contain a scalar quantity?

A. displacement, acceleration, force
B. acceleration, speed, work
C. energy, work, distance
D. velocity, force, power

Answer 7

A. displacement, acceleration, force

Question 8

What is the SI unit of luminous
intensity?

A. Candlepower
B. Lux
C. Lumens
D. Candela

Answer 8

D. Candela

The candela is the base unit of
luminous intensity in the International
System of Units; that is, luminous power
per unit solid angle emitted by a point
light source in a particular direction.

Question 9

___ is one whose action is not
confined to or associated with a unique
line in space.

A. Free Vector
B. Sliding Vector
C. Absolute Vector
D. Fixed Vector

Answer 9

A. Free Vector

A vector whose point of application is
not fixed but magnitude and direction is,
is called free vector. Fixed or localized
vector is whose point of application is fixed. Same vector can become free or fixed depending on scenario.

Question 10

The mechanical advantage of any
machine is:

A. the ratio of the force exerted by the
machine to the force applied to it
B. the ratio of the work done by the machine
to the work expended on it
C. the efficiency of the machine
D. the work done by the machine

Answer 10

A. the ratio of the force exerted by the
machine to the force applied to it

Question 11

Which of the following is NOT an
example of accelerated motion?

A. Earth’s motion about sun
B. Horizontal component of projectile
motion
C. Vertical component of projectile motion
D. Circular motion at constant speed

Answer 11

B. Horizontal component of projectile
motion

Question 12

When a body moves with a constant
speed along a circle

A. no work is done on it
B. no force acts on it
C. its velocity remains constant
D. no acceleration is produced in it

Answer 12

A. no work is done on it

Solution: On circular motion, the force acts along the radius and displacement at a location is perpendicular to the radius i.e., θ=90°

Question 13

Name the fundamental force which
holds the planets in their orbits around
the sun.

A. Electro static force of attraction
B. Nuclear force of attraction
C. Electrostatic static force of attraction
D. Gravitational force of attraction

Answer 13

D. Gravitational force of attraction

Gravitation is a natural phenomenon by which all objects with mass attract each other, and is one of the fundamental
forces of physics. Gravity is the force
that pulls us to the surface of the Earth,
keeps the planets in orbit around the
Sun and causes the formation of
planets, stars and galaxies.

Question 14

The momentum of an object at a given
instant is independent of its:

A. Mass
B. Speed
C. Velocity
D. Acceleration

Answer 14

D. Acceleration

Question 15

One slug is equivalent to how many kg?

A. 14.6 kg
B. 15.5 kg
C. 12.8 kg
D. 13.2 kg

Answer 15

A. 14.6 kg

1 slug = 14.6 kg
1 kg =1000 grams
1 kg = 2.2046 pounds
1 ounce = 28.35 grams
1 pound = 16 ounces
1 ton = 2000 pounds
1 ton = 907.19 kg
1 metric ton = 1000 kg

Question 16

What is the SI unit of work?

A. Joule
B. Watt
C. Newton
D. Newton-Second

Answer 16

A. Joule

The joule (J) is a derived unit of energy in the International System of Units. It is equal to the energy transferred to (or
work done on) an object when a force of
one newton acts on that object in the
direction of its motion through a
distance of one meter (1 newton meter
or Nm)

Question 17

What refers to the force that holds part
of the rigid body together?

A. Internal force
B. Natural force
C. Concentrated force
D. External force

Answer 17

A. Internal force

Internal Forces are forces between objects found inside the system. It cannot do work on system cannot change total energy of the system.

External forces are forces that act on
the system and their agents are part of
the environment. It can do work on
system. It can transfer energy into or
out of system, thus changing the total.

Question 18

The kinetic energy of a stone falling
near the earth’s surface through a
vacuum increases with the:

A. square root of its velocity
B. square of its velocity
C. cube root of its velocity
D. cube of its velocity

Answer 18

B. square of its velocity

Kinetic energy is the energy possessed
by an object because of its motion.
KE = 1/2 mv^2

Question 19

The ____ of a pivotal object is that point at which it can be struck without producing a reaction force on its pivot.

A. center of oscillation
B. axis of oscillation
C. center of gravity
D. center of mass

Answer 19

A. center of oscillation

The same point is called the center of
oscillation for the object suspended
from the pivot as a pendulum, meaning that a simple pendulum with all its mass concentrated at that point will have the same period of oscillation as the compound pendulum.

Question 20

A wave in which the particles of the
material move up and down as the wave
goes from left to right is called:

A. standing wave
B. longitudinal wave
C. none of these choices
D. transverse wave

Answer 20

D. transverse wave

A wave in which the particles of the
material move up and down as the wave
goes from left to right is called transverse wave.

Transverse waves are waves in which the vibration direction is perpendicular to the direction of the wave propagation.
Examples are wave on string, water waves and electromagnetic waves (light and radio waves).

Question 21

How many decibels should a sound to
be barely audible?

A. 0
B. 0.1
C. 1
D. 1.5

Answer 21

A. 0

The threshold of hearing is assigned a sound level of 0 decibels (abbreviated 0 dB); this sound corresponds to an intensity of 1*10W/m. For a sound to be at least audible, it should have a sound level of 0 dB

Question 22

Which statement accurately describes the energy of a spring-mass system in simple harmonic motion?

A. The mechanical energy of the spring-mass
system decreases as the object is
displaced from its equilibrium, resulting in
an increase in its kinetic energy.
B. The mechanical energy of the spring-mass
system is solely determined by the
maximum potential energy it can
experience.
C. The mechanical energy of the spring-
mass system remains constant, with
potential energy at its maximum when
kinetic energy is at a minimum.
D. The kinetic energy of the spring-mass system is always zero during simple harmonic motion.

Answer 22

C. The mechanical energy of the spring-
mass system remains constant, with
potential energy at its maximum when
kinetic energy is at a minimum.

Question 23

The unit for the period is

A. m*s
B. T
C. s
D. /s

Answer 23

C. s

Period is the time it takes for one
complete cycle. Second (s) is the Sl unit
for time.

Question 24

A standing wave is formed on a tightly stretched string. The distance between a node and an antinode is:

A. 1/4 wavelength
B. 1/2 wavelength
C. 1 wavelength
D. 1/8 wavelength

Answer 24

A. 1/4 wavelength

Question 25

The unit for wavelength is

A. m*s
B. /m
C. m
D. m/s

Answer 25

C. m

Wavelength is the distance (in meters)
traveled by an electromagnetic wave
during the time of one cycle.

Question 26

Sound waves are an example of what
type of wave?

A. compressional and longitudinal
B. longitudinal
C. transverse
D. compressional

Answer 26

A. compressional and longitudinal

Sound waves are disturbances or
vibration whose energy must be
communicated into a medium. It is an
example of a longitudinal mechanical
wave that can travel through solid, liquid
or gas.

Question 27

What is meant by radius of curvature
when describing rotational motion?

A. The radius of curvature is the radius of
a circular path.
B. The radius of curvature is the area of a
circular path
C. The radius of curvature is the
circumference of a circular path.
D. The radius of curvature is the diameter of a
circular path.

Answer 27

A. The radius of curvature is the radius of
a circular path.

In rotational motion, the radius of
curvature refers to the radius of the
circle along which an object is moving
in a curved path. It represents the
distance from the center of the circle to any point on its circumference. In other words, it determines the size of the
circular path followed by an object
during rotational motion.

Question 28

What is the sound level of the threshold
of pain?

A. 130 dB
B. 100 dB
C. 120 dB
D. 110 dB

Answer 28

C. 120 dB

The threshold of pain is the SPL beyond which sound becomes unbearable for a human listener. This threshold varies
only slightly with frequency. Prolonged
exposure to sound pressure levels in
excess of the threshold of pain can cause physical damage, potentially leading to hearing impairment.

Question 29

Which of the following does not travel in
a vacuum?

A. magnetic waves
B. gamma rays
C. radio waves
D. sound waves

Answer 29

D. sound waves

Sound waves are disturbances or
vibration whose energy must be
communicated into a medium. It is an
example of a longitudinal mechanical
wave that can travel through solid, liquid
or gas.

Question 30

When waves go from one place to
another, they transport

A. energy and matter
B. wavelength and matter
C. energy only
D. frequency only

Answer 30

C. energy only

When waves go from one place to
another, they transport energy only.
Waves such as sound or light cannot
are not capable of transporting matter.

Question 31

At what intensity will sound wave starts
to damage the ear of humans.

A. 10 W/m
B. 0.1 W/m
C. 1 W/m
D. 0.01 W/m

Answer 31

C. 1 W/m

The human ear has an incredibly large
range, being able to detect sound
intensities from 1 x 10W / m to 1 W/ m.Sound waves beyond that intensity tend to cause damage to human ears.

Question 32

Sound waves in air are

A. longitudinal
B. transverse
C. either longitudinal or transverse
D. stationary

Answer 32

A. longitudinal

Sound waves are disturbances or
vibration whose energy must be
communicated into a medium. It is an
example of a longitudinal mechanical
wave that can travel through solid, liquid
or gas.

Question 33

If viewed on an oscilloscope, the
loudness of a sound wave would be
associated with the wave’s:

A. velocity
B. frequency
C. amplitude
D. wavelength

Answer 33

C. amplitude

If viewed on an oscilloscope, the
loudness of a sound wave would be
associated with the wave’s amplitude.
The higher the amplitude, the louder the
sound.

Question 34

A room has a window made from thin
glass. The room is colder than the air
outside. There is some condensation on the glass window. On which side of the glass would the condensation most likely be found?

A. Condensation is on the outside of the
glass when the cool, dry air outside the
room comes in contact with the cold pane
of glass.
B. Condensation is on the inside of the
glass when the warm, moist air inside
the room comes in contact with the
cold pane of glass.
C. Condensation is on the inside of the glass
when the cool, dry air inside the room
comes in contact with the cold pane of
glass.
D. Condensation is on the outside of the
glass when the warm, moist air outside the room comes in contact with the cold pane of glass.

Answer 34

B. Condensation is on the inside of the
glass when the warm, moist air inside
the room comes in contact with the
cold pane of glass.

Question 35

What kind of heat transfer requires no
medium?

A. convection
B. conduction
C. reflection
D. radiation

Answer 35

D. radiation

Radiation is the type of heat transfer
that requires no medium, as it involves
the transfer of heat through
electromagnetic waves that can travel through vacuum or empty space, unlike conduction and convection, which
require a material medium to transfer
heat.

Question 36

The pressure of 1 bar is equivalent to
how many Pascal?

A. 100,000
B. 1,000,000
C. 10,000
D. 1000

Answer 36

A. 100,000

The bar is defined using the SI derived
unit, Pascal: 1 bar = 100,000 Pa =
100,000 N/m2.

Question 37

What is an elemental unit of energy?

A. Quark
B. Photon
C. Quartz
D. Quantum

Answer 37

D. Quantum

In physics, a quantum (plural: quanta) is
the minimum amount of any physical
entity involved in an interaction. The
fundamental notion that a physical
property may be “quantized” is referred to as “the hypothesis of quantization”.This means that the magnitude of the physical property can take on only discrete values consisting of integer
multiples of one quantum.

Question 38

Which one is equivalent of the unit
“Pascal’?

A. N/nm
B. N/m
C. N/m
D. N/nm

Answer 38

C. N/m

One Pascal is equivalent to 1 N of force per 1 unit area. It can also be expressed in 1 kg-m’s

Question 39

Property of fluid that describes its
internal resistance is known as:

A. Friction
B. Viscosity
C. Internal energy
D. Resistance

Answer 39

B. Viscosity

Viscosity is the measure of a fluid’s
internal resistance to flow, determining
how easily it flows or its thickness/
stickiness.

Friction is the force that opposes the relative motion or tendency of motion between two surfaces in contact.

Resistance refers to the opposition or
hindrance to the flow of current in
electrical circuits.

Internal energy is the total energy
contained within a thermodynamic
system, including both its kinetic and
potential energy components.

Question 40

The process of heat transfer from one particle of the body to another without actual motion of the particle is called

A. Conduction
B. None of these choices
C. Radiation
D. Convection

Answer 40

C. Radiation

The process of heat transfer from one particle of the body to another without actual motion of the particle is called
radiation, where electromagnetic waves
(such as infrared radiation) carry the
thermal energy from a higher-temperature body to a lower-temperature one without the need for a medium or direct contact between the particles.

Question 41

Heat transfer takes place according to

A. Second Law of Thermodynamics
B. First Law of Thermodynamics
C. Zeroth Law of Thermodynamics
D. Third Law of Thermodynamics

Answer 41

A. Second Law of Thermodynamics

The Second Law of Thermodynamics governs the direction of heat transfer,indicating that heat will always flow in the direction that increases the entropy of the system, which means it moves
from higher temperature regions to
lower temperature regions until thermal
equilibrium is reached.

Question 42

The induced voltage across a stationary conductor in a stationary magnetic field is

A. increased
B. reversed in polarity
C. decreased
D. Zero

Answer 42

D. Zero

When a stationary conductor is placed
in a stationary magnetic field, no
induced voltage is generated. This is
because in order to induce a voltage,
there must be relative motion between the conductor and the magnetic field. In this scenario, both the conductor and
the magnetic field are stationary, so
there is no change in the magnetic flux
passing through the conductor.

Question 43

What do you call the characteristic of a magnetic material whereby a change in magnetization lags the application of a magnetizing force?

A. Induction
B. Reluctance
C. Hysteresis
D. Retentivity

Answer 43

C. Hysteresis

Hysteresis: The characteristic of a
magnetic material whereby a change in magnetization lags the application of a magnetizing force.

Induction: The production of an
electromotive force (voltage) in a closed circuit due to a change in the magnetic field through the circuit.

Retentivity: The ability of a magnetic
material to retain its magnetization even
after the magnetizing force is removed.

Reluctance: The opposition offered by a magnetic material to the establishment of magnetic flux when subjected to a
magnetic field.

Question 44

All images formed by diverging lenses
are:

A. Real, inverted and diminished.
B. Real, upright and enlarged.
C. Virtual, upright and diminished.
D. Virtual, inverted and enlarged.

Answer 44

C. Virtual, upright and diminished.

Diverging lenses always produce virtual
images, meaning the light rays do not
actually converge to a physical point.These virtual images are also upright,having the same orientation as the object, and they appear smaller than the actual object, thus being diminished.

Question 45

Virtual images are so called because:

A. The image can only be projected onto a
screen.
B. The image is too small to be seen with the
naked eye.
C. The image is located behind the lens or
mirror.
D. Light rays that form the image only appear to come from the position where the image is.

Answer 45

D. Light rays that form the image only appear to come from the position where the image is.

Virtual images are called so because
they are formed by the apparent
extension of light rays backward, giving the illusion that the light rays originate from the position where the image is located, even though they do not actually pass through that position.
These images cannot be projected onto
a screen and are perceived as if they
exist in a location behind the lens or mirror from where the light seems to originate.

Question 46

Photons always propagate with speed c,
but light appears to travel at a speed
different from c in dense media. How
can we account for this phenomenon?

A. Light is slowed down because it does not take a straight-line path through the dense medium.
B. Electron oscillators in the medium introduce a phase change upon re radiation.
C. A medium is a different reference frame to vacuum, so the difference in the observed speed of light is a consequence of
relativity.
D. Propagation in media depends on reradiation by electron-oscillators, which takes a finite time to occur.

Answer 46

B. Electron oscillators in the medium introduce a phase change upon re radiation.

When light travels through a dense
medium, it interacts with the charged
particles (electrons) in the medium,
causing them to oscillate and re-radiate
the light. This process introduces a
phase change in the wave, effectively
slowing down the overall propagation of light through the medium while photons themselves still travel at the speed of light (c) in vacuum.

Question 47

The spectrum observed when white light is shone through a prism is best explained by:

A. Dispersion
B. Diffraction
C. Distortion
D. Dichroism

Answer 47

A. Dispersion

When white light passes through a
prism, it undergoes dispersion, which
means that different colors
(wavelengths) of light are refracted by different amounts, causing the light to spread out into its constituent colors,creating a spectrum of colors.

Question 48

Total internal reflection can occur:

A. Only when the media are of approximately
equal density.
B. Only when the incident medium is denser
than the transmitting medium.
C. Only when the incident medium is less
dense than the transmitting medium.
D. Irrespective of the density of the media

Answer 48

C. Only when the incident medium is less
dense than the transmitting medium.

Total internal reflection occurs when
light travels from a medium with a
higher refractive index (denser medium)
to a medium with a lower refractive
index (less dense medium) at an angle
of incidence greater than the critical
angle. In such cases, instead of
refracting out of the interface, the light
reflects back into the denser medium,
with no transmission into the less dense
medium.

Question 49

Images formed by a convex mirror are:

A. Always real.
B. Always upright.
C. Always enlarged.
D. Always farther from the mirror than the
focus.

Answer 49

B. Always upright.

Images formed by a convex mirror are always upright, meaning they have the same orientation as the object.
Additionally, they are virtual images,
meaning they cannot be projected onto a screen, and they are located closer to the mirror than the actual object.
The size of the image depends on the
distance of the object from the mirror
and its focal length, and it can be either
enlarged or reduced.

Question 50

The polarity of induced voltage while a
field is collapsing is

A. present only if the force is stationary
B. opposite to the force creating the field
C. identical to the force creating the field
D. independent of the force creating the field

Answer 50

B. opposite to the force creating the field

When a magnetic field collapses, the
induced voltage is generated in a
direction opposite to the force that
initially created the magnetic field,
according to Lenz’s law. This induced voltage works to oppose the change in magnetic flux, leading to a polarity that counteracts the original magnetic field.

Question 51

When the current through the coil of an
electromagnet reverses, the

A. direction of the magnetic field reverses
B. direction of the magnetic field remains unchanged
C. magnetic field expands
D. magnetic field collapses

Answer 51

A. direction of the magnetic field reverses

When the current through the coil of an electromagnet reverses, the direction of the magnetic field produced by the
electromagnet also reverses, following the right-hand rule for the magnetic field around a current-carrying conductor.

Question 52

What do you call the characteristic of a magnetic material whereby a change in magnetization lags the application of a magnetizing force?

A. Induction
B. Hysteresis
C. Retentivity
D. Reluctance

Answer 52

B. Hysteresis

Hysteresis: The characteristic of a
magnetic material whereby a change in magnetization lags the application of a magnetizing force.

Induction: The production of an
electromotive force (voltage) in a closed circuit due to a change in the magnetic field through the circuit.

Retentivity: The ability of a magnetic
material to retain its magnetization even after the magnetizing force is removed.

Reluctance: The opposition offered by a magnetic material to the establishment of magnetic flux when subjected to a
magnetic field.

Question 53

When the north poles of two bar
magnets are brought close together,
there will be

A. a force of repulsion
B. no force
C. a downward force
D. a force of attraction

Answer 53

A. a force of repulsion

When the north poles of two bar
magnets are brought close together,
they will experience a force of repulsion In a bar magnet, the north pole is where the magnetic field lines exit, while the
south pole is where the magnetic field lines enter. When two north poles are brought close together, the magnetic
field lines from both magnets repel each
other, causing a force that pushes the
magnets away from each other.

Question 54

Which electromagnetic device uses
brushes and a commutator?

A. A relay
B. A speaker
C. A solenoid
D. A dc generator

Answer 54

D. A dc generator

A dc generator, also known as a direct
current generator, is an electromagnetic
device that uses brushes and a
commutator. The commutator is a
rotary switch that reverses the direction
of the current in the coils of the
generator as it rotates, ensuring that the
output voltage remains unidirectional
(direct current). The brushes maintain
electrical contact with the rotating
commutator, allowing the current to
flow to the external circuit.

Question 55

What are the effects of moving a closed
wire loop through a magnetic field?

A. The polarity across the wire depends on
the direction of motion.
B. A current is induced in the wire.
C. All of these choices
D. A voltage is induced in the wire.

Answer 55

C. All of these choices

When a closed wire loop is moved
through a magnetic field, several effects
are observed:

A voltage is induced in the wire: This
phenomenon is known as
electromagnetic induction. When the
loop cuts through the magnetic field
lines, the magnetic flux through the loop
changes, which, in turn, induces a
voltage across the loop.

A current is induced in the wire: The
induced voltage can drive an electric
current to flow through the wire loop if
the circuit is closed. This is a
consequence of Faraday’s law of
electromagnetic induction. The induced current flows in a direction that opposes the change in magnetic flux, following Lenz’s law.

The polarity across the wire depends on the direction of motion: The polarity of the induced voltage (and thus the
direction of the induced current) is
determined by the direction of motion of
the wire loop relative to the magnetic
field. The polarity changes when the
direction of motion changes.

Question 56

Pressure is equal to:

A. force divided by area
B. Area divided by force
C. area times force
D. area minus force

Answer 56

A. force divided by area

Pressure is defined as the force per unit area, measured in Pascal defined as one Newton per square meter.

Question 57

Processes which occur without the
addition or withdrawal of heat from the
surrounding are called what?

A. adiabatic
B. isotropic
C. isochoric
D. isothermal

Answer 57

A. adiabatic

Types of Processes

1. Isobaric process is process carried
   out at constant pressure
2. Isovolumic process also known as
   isometric or isochoric process is a
   process carried out at constant volume
3. Adiabatic process is one which no
   heat or other energy is transferred to or
   from the system.
   a. Isentropic process is an adiabatic process in which there is no change in the system entropy.
   b. Throttling process is an adiabatic
   process in which there is no change in the system enthalpy but for which there is a significant pressure drop.
4. Isothermal process is a process
   carried out at constant temperature.

Question 58

Which of the following engine is the
most efficient?

A. gasoline engine
B. diesel engine
C. gas turbine
D. Carnot cycle

Answer 58

D. Carnot cycle

Question 59

The volume of a gas under constant pressure increases or decrease with temperature

A. Ideal Gas Law
B. Charles’ Law
C. Gay-Lussac’s Law
D. Boyle’s Law

Answer 59

B. Charles’ Law

Charles’ law states that if the pressure
remained constant within a closed
system, the volume of the gas varies
directly with the temperature during the change of state. At constant pressure,gas volume increases when the temperature is raised and vice versa.

Boyle’s law states that if the
temperature remained constant within a
closed system, the volume of the gas
varies inversely with the pressure during
the change of state.

Gay-Lussac’s law states that the
pressure of an ideal gas, if held at a
constant volume is directly proportional
to its temperature at any change of
state.

Question 60

Which of the laws of Thermodynamics is often invoked to discredit attempts at perpetual motion?

A. Third Law of Thermodynamics
B. Second Law of Thermodynamics
C. First Law of Thermodynamics
D. Zeroth Law of Thermodynamics

Answer 60

B. Second Law of Thermodynamics

Second Law of Thermodynamics
-Heat energy flows spontaneously from
hotter to a colder object, but not vice
versa
-No heat engine that cycle continuously can change all its input energy to useful work
-If a system undergoes spontaneous
change, it will change in such a way that
its entropy will increase or, at best,
remain constant.

Question 61

Which of the following terms refer to the
amount of heat needed to raise the
temperature of a unit mass of a
substance through one degree?

A. Heat of fusion
B. Liquification heat
C. Specific heat
D. Internal heat

Answer 61

C. Specific heat

Specific Heat is the amount of heat
required to change the temperature of
one gram of a substance by 1.
For water, Cw = 1 cal/g-C.
For ice, Ci = 0.5 cal/g-C.

Question 62

The difference between the absolute pressure and the local atmospheric pressure is called the:

A. Relative pressure
B. Standard pressure
C. Gauge pressure
D. Vacuum pressure

Answer 62

C. Gauge pressure

Gauge Pressure is a pressure difference
between the system and the
atmospheric pressure. An ordinary
pressure gauge will have a reading of
zero, this simply means that there is no
excess pressure other than the atmospheric pressure.

Question 63

A thermometer reads 50 degrees on a
cold January day in New Delhi. The
reading is on the scale

A. Celsius
B. Fahrenheit
C. absolute
D. Centigrade

Answer 63

B. Fahrenheit

50°C is relatively hot and 50°F is
relatively cold. Since it is stated in the
problem that it is on a cold January day,
the reading is probably on Fahrenheit
scale.

Question 64

The work output of every heat engine

A. depends only on its exhaust temperature
B. equals the difference between its heat
intake and the heat exhaust
C. equals that of a Carnot engine with the
same intake and exhaust temperatures
D. depends only on its intake temperature

Answer 64

B. equals the difference between its heat
intake and the heat exhaust

Question 65

The number of Joules per gram required
to melt ice at its melting point is called:

A. Heat of vaporization
B. Sublimation
C. Vapor pressure
D. Heat of fusion

Answer 65

D. Heat of fusion

Latent Heat of Fusion is the heat
necessary to change a unit mass of a substance from solid to liquid state or from liquid to solid state at its melting point.
For H20, 144 BTU/Ib or 80 cal/g or 334 kJ/kg.

Question 66

The transfer of energy between a solid surface and the adjacent fluid that is in motion, and it involves the combined
effects of conduction and fluid motion
is called

A. radiation
B. Convection
C. Conduction
D. emission

Answer 66

B. Convection

Modes of Transmission of Heat

Conduction - heat transfer of energy from the more energetic particles of a substance to the adjacent less energetic ones as a result of interaction between particles.

Convection - heat transfer of energy
between a solid surface and the
adjacent fluid that is in motion, and it
involves the combined effects of
conduction and fluid motion.

Radiation - energy emitted by matter in the form of electromagnetic waves (or photons) as a result of the changes in the electronic configurations of the atoms or molecules.

Question 67

Whenever you have equal volumes of gases at the same temperature and pressure, the volume must

A. Contain 2.4 milliliters of STP
B. Contain one mole of any gas at STP
C. Contain the Avogadro’s number
D. Contain equal number of particles

Answer 67

D. Contain equal number of particles

Question 68

The boundaries of a control volume are
called:

A. control area
B. control surface
C. control line
D. volume control

Answer 68

B. control surface

A control volume is a fixed region in
space chosen for the thermodynamic study of mass and energy balances for flowing systems. The boundary of the control volume may be a real or imaginary envelope.

The control surface is the boundary of the control volume.

Question 69

The amount of energy needed to
change a given mass of ice to water at constant temperature is called the heat of

A. formation
B. crystallization
C. condensation
D. fusion

Answer 69

D. fusion

Question 70

Which of the following is not an
example of radiation?

A. an incandescent bulb generating heat
B. a microwave oven cooking food
C. an open window cooling down a room
D. a sun warming a planet

Answer 70

C. an open window cooling down a room

An open window cooling down a room
is an example of convection

Question 71

What is a monochromatic light?

A. Light with many colors
B. Light with only one color and one
wavelength
C. Light with only one color
D. Light with only one wavelength

Answer 71

B. Light with only one color and one
wavelength

The term monochromatic comes from the Greek words mono, meaning single,and chroma, meaning color. So
monochromatic light literally means
light of one color. In scientific terms, it
means light of a single wavelength.

Question 72

The Weber and the Maxwell are units of
measure of:

A. relative speed
B. electrical current
C. conductance
D. magnetic flux

Answer 72

D. magnetic flux

Weber - Sl unit of magnetic flux equal to 10 lines or maxwells. Named after the German physicist Wilhelm Weber (1804-1891)

Maxwell - cgs unit of magnetic flux
equal to one line of force. Named after
the Scottish physicist, James Clerk
Maxwell (1831-1879)

Question 73

Which one of the following is the
advantage of connecting two dry cells in
parallel instead of in series?

A. generates heat in an external circuit half as
fast as would a single cell
B. has half the internal resistance of a
single cell
C. gives twice the EMF of one dry cell
D. has no internal resistance

Answer 73

B. has half the internal resistance of a
single cell

Connection two dry cells in parallel
instead of in series has half the internal
resistance of a single cell.

Question 74

At a point halfway between two
identical point charges, the electric field
is equal to:

A. its maximum value
B. pointing away from the two charges
C. half its maximum value
D. zero

Answer 74

D. zero

At the midpoint between two identical charges, the resultant electric field is zero.

Question 75

The transfer of energy due to the
emission of electromagnetic waves (or
photons) is called:

A. Conduction
B. emission
C. Convection
D. radiation

Answer 75

D. radiation

Modes of Transmission of Heat

Conduction - heat transfer of energy from the more energetic particles of a substance to the adjacent less energetic ones as a result of interaction between particles.

Convection - heat transfer of energy
between a solid surface and the
adjacent fluid that is in motion, and it
involves the combined effects of
conduction and fluid motion.

Radiation - energy emitted by matter in the form of electromagnetic waves (or photons) as a result of the changes in the electronic configurations of the atoms or molecules.

Question 76

What is the wavelength band in
nanometer of visible light?

A. 300-700
B. 350-800
C. 300-800
D. 350-700

Answer 76

D. 350-700

Electromagnetic radiation in this range of wavelengths is called visible light or simply light. A typical human eye will
respond to wavelengths from about 390
to 700 nm. In terms of frequency, this
corresponds to a band in the vicinity of
430-770 THz.

Question 77

Which one of the following laws best describes the operation of an electric generator?

A. Faraday’s Law of Induction
B. Ampere’s Law
C. Ohm’s Law for Conductors
D. Gauss’ Law

Answer 77

A. Faraday’s Law of Induction

Faraday’s Law of Induction best
describes the operation of an electric
generator. Faraday’s law of induction is
a basic law of electromagnetism
predicting how a magnetic field will
interact with an electric circuit to
produce an electromotive force -a
phenomenon known as electromagnetic
induction.

Question 78

What are high-frequency
electromagnetic waves emitted when
fast electrons impinge on matter?

A. X-rays
B. Beta rays
C. De Broglie waves
D. Alpha rays

Answer 78

A. X-rays

X-rays are electromagnetic waves with wavelengths in the range of 0.01 to 10 nanometers, corresponding to
frequencies in the range 30 petahertz to
30 exahertz (3x10 Hz to 3x10 Hz) and
energies in the range 100 eV to 100 keV.They are shorter in wavelength than UV rays and longer than gamma rays.

Question 79

The transfer of energy from the more
energetic particles of a substance to the adjacent less energetic ones as a result of interaction between particles is
called:

A. Convection
B. emission
C. radiation
D. Conduction

Answer 79

D. Conduction

Modes of Transmission of Heat

Conduction - heat transfer of energy from the more energetic particles of a substance to the adjacent less energetic ones as a result of interaction between particles.

Convection - heat transfer of energy
between a solid surface and the
adjacent fluid that is in motion, and it
involves the combined effects of
conduction and fluid motion.

Radiation - energy emitted by matter in the form of electromagnetic waves (or photons) as a result of the changes in the electronic configurations of the atoms or molecules.

Question 80

What consists of various wavelengths
of light emitted by an excited
substance?

A. Emission spectrum
B. Excited spectrum
C. Light spectrum
D. Absorption spectrum

Answer 80

B. Excited spectrum

When electrons go from the excited
state to the ground state, there is a loss
of vibrational energy. As a result, the
emission spectrum is shifted to longer
wavelengths than the excitation
spectrum (wavelength varies inversely
to radiation energy).

Question 81

Two parallel wires carrying currents in
opposite directions will:

A. not affect each other
B. attract each other
C. repel each other
D. cause an electric arc to form

Answer 81

C. repel each other

The direction is obtained from the right hand rule. Note that two wires carrying current in the same direction attract each other, and they repel if the currents are opposite in direction.

Question 82

When a metal becomes a
superconductor, there is a tremendous
decrease in its:

A. density
B. total volume
C. electrical resistance
D. length

Answer 82

C. electrical resistance

A superconductor is a substance that conducts electricity without resistance when it becomes colder than a “critical temperature.”

Question 83

Which of the following phenomena
suggest that light may be a transverse
wave?

A. diffraction
B. polarization
C. reflection
D. photoelectric effect

Answer 83

B. polarization

Polarization is a property applying to transverse waves that specifies the geometrical orientation of the oscillations. In a transverse wave, the
direction of the oscillation is
perpendicular to the direction of motion
of the wave.

Question 84

What type of mirror that curves outward toward its center and diverges parallel light as though the reflected light came from a single virtual focal point behind the mirror?

A. Concave mirror
B. Spherical mirror
C. Convex mirror
D. Chromatic mirror

Answer 84

C. Convex mirror

A convex mirror, diverging mirror, or fish
eye mirror is a curved mirror in which
the reflective surface bulges toward the light source. Convex mirrors reflect light outwards, therefore they are not used to focus light. Such mirrors always form a virtual image.

The passenger-side mirror on a car is
typically a convex mirror. In some
countries, these are labeled with the safety warning “Objects in mirror are closer than they appear”, to warn the driver of the convex mirror’s distorting effects on distance perception.

Question 85

What device is used for producing a
narrow, monochromatic, coherent beam
of light?

A. Fiber optic
B. Spectral device
C. Laser
D. Prism

Answer 85

C. Laser

A laser is a device that emits light
through a process of optical
amplification based on the stimulated emission of electromagnetic radiation. The term “laser” originated as an acronym for
“light amplification bystimulated emission of radiation”

Question 86

In translucent material,

A. the reflected energy is absorbed within a
thick layer and converted to heat
B. light is partially absorbed
C. the refracted energy is absorbed within a
very thin layer and converted to heat
D. light is able to pass through

Answer 86

B. light is partially absorbed

A translucent material lets light pass through, but objects on the other side can’t be seen clearly. Frosted glass is
translucent material. Translucent means
that light may pass through that
material but images on the other side of
that material are not clearly visible.

Question 87

What type of lens deviates parallel light
outward as though it originated at a
single virtual focal point?

A. Microscopic lens
B. Magnifying lens
C. Divergent lens
D. Convergent lens

Answer 87

C. Divergent lens

A lens that is thinner in the middle and fatter at the edges is called a concave or diverging lens. When you look through a diverging lens, everything seems smaller. These lenses produce
virtual images.