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.