Physics

Question 1

SI unit of amount of substance.

Answer 1

Mole

Question 2

SI unit of luminous intensity

Answer 2

Candela

Question 3

A cylinder with platinum-iridium alloy is used to define the kilogram. What is the name of this cylinder?
a. Le Grand K
b. pti alloy
c. standard kilogram
d. standard mass

Answer 3

a. Le Grand K

Question 4

What is the cgs unit of force?
a. Newton
b. erg
c. dyne
d. poise

Answer 4

c. dyne

Question 5

Only used when recording any measurements.

Answer 5

Uncertain digits

Question 6

Only use when you are multiplying or dividing measured numbers

Answer 6

Significant Figures

Question 7

These are always significant

Answer 7

1. Nonzero numbers
2. Sandwiched zeros
3. Zeros that fall both at the end of the number and after the decimal point

Question 8

These will never be significant number

Answer 8

zeros that act as placeholders

Question 9

It is usually stated that every particle attracts every other particle in the universe with a force which is directly proportional to the product of their masses and inversely proportional to the square of the distance between their centers.

Answer 9

Law of Universal gravitation

Question 10

The “triple point” of a substance is that point for which the temperature and pressure are such that:

Answer 10

solid, liquid, and vapor are all in equilibrium

Question 11

the lowest velocity which a body must have in order to escape the gravitational attraction of a particular planet or other object.

Answer 11

Escape Velocity

Question 12

thermal energy whose transfer to or from a substance results in a change of temperature

Answer 12

Sensible heat

Question 13

the heat required to convert a solid into a liquid or vapor, or a liquid into a vapor, without change of temperature.

Answer 13

Latent heat

Question 14

The amount of heat required to change 1 g of a substance at the temperature of its melting point from the solid to the liquid state without changing temperature.

Answer 14

Latent heat of fusion

Question 15

It is defined as the heat required to change one mole of liquid at its boiling point under standard atmospheric pressure.

Answer 15

Latent heat of vaporization

Question 16

Which one of the following statements is true?
a. Temperatures differing by 25◦ on the Fahrenheit scale must differ by 45◦ on the Celsius scale
b. 40K corresponds to −40◦ C
c. Temperatures which differ by 10◦ on the Celsius scale must differ by 18◦ on the Fahrenheit scale
d. Water at 90◦ C is warmer than water at 202◦ F

Answer 16

c. Temperatures which differ by 10◦ on the Celsius scale must differ by 18◦ on the Fahrenheit scale

Question 17

statement that the total radiant heat power emitted from a surface is proportional to the fourth power of its absolute temperature.

Answer 17

Stefan-Boltzmann Law

Question 18

a law stating that the ratio of the sines of the angles of incidence and refraction of a wave are constant when it passes between two given media.

Answer 18

Snell’s law

Question 19

The light ray can actually bend so much that it never goes beyond the boundary between the two media.

Answer 19

total internal reflection.

Question 20

the scientific study of sight and the behavior of light, or the properties of transmission and deflection of other forms of radiation.

Answer 20

Optics

Question 21

The type of lens used to cure farsightedness is ______________ lens. a. Concave b. Convex c. Biconcave d. Plano – convex

Answer 21

Convex

Question 22

The laws of physics are the same for all observers in any inertial frame of reference relative to one another

Answer 22

Relativity

Question 23

Two events, simultaneous for one observer, may not be simultaneous for another observer if the observers are in relative motion.

Answer 23

Relative of Simultaneity

Question 24

Moving clocks are measured to tick more slowly than an observer’s “stationary” clock.

Answer 24

Time dilation

Question 25

Objects are measured to be shortened in the direction that they are moving with respect to the observer.

Answer 25

Length contraction

Question 26

No physical object, message or field line can travel faster than the speed of light in a vacuum.

Answer 26

Maximum speed is finite

Question 27

energy and mass are equivalent and transmutable.

Answer 27

Mass-energy equivalence

Question 28

Clocks run slower in deeper gravitational wells.

Answer 28

Gravitational Time Dilation

Question 29

Orbits precess in a way unexpected in Newton's theory of gravity. (This has been observed in the orbit of Mercury and in binary pulsars).

Answer 29

Precession

Question 30

Rays of light bend in the presence of a gravitational field

Answer 30

Light defraction

Question 31

Rotating masses "drag along" the spacetime around them.

Answer 31

Frame Dragging

Question 32

the universe is expanding, and the far parts of it are moving away from us faster than the speed of light.

Answer 32

Metric Expansion of space

Question 33

it deals with the study of light and particles at atomic and smaller level

Answer 33

Quantum mechanics

Question 34

states that the current through a conductor between two points is directly proportional to the voltage across the two points.

Answer 34

Ohm's Law

Question 35

Nuclear sizes are expressed in a unit named a. Fermi c. Newton b. Angstrom d. Tesla

Answer 35

Fermi

Question 36

Lightyear is a unit of a. time c. light b. distance d. intensity of light

Answer 36

b. distance

Question 37

Mirage is due to a. unequal heating of different parts of atmosphere b. magnetic disturbances in the atmosphere c. depletion of ozone layer in the atmosphere d. equal heating of different parts of the atmosphere

Answer 37

a. unequal heating of different parts of atmosphere

Question 38

Stars appears to move from east to west because a. all stars move from east to west b. the earth rotates from west to east c. the earth rotates from east to west d. the background of the stars moves from west to east

Answer 38

b. the earth rotates from west to east

Question 39

If two bodies of different masses, initially at rest, are acted upon by the same force for the same time, then both bodies acquire the same a. velocity c. acceleration b. momentum d. kinetic energy

Answer 39

b. momentum

Question 40

Out of the following, which is not emitted by radioactive substances? a. electrons b. electromagnetic radiations c. alpha particles d. neutrons

Answer 40

d. neutrons

Question 41

Sound waves in air are a. transverse c. electromagnetic b. longitudinal d. polarized

Answer 41

b. longitudinal

Question 42

Materials for a rain-proof coats and tents owe their water-proof properties to a. surface tension c. specific gravity b. viscosity d. elasticity

Answer 42

a. surface tension

Question 43

It takes much longer to cook food in the hills than in the plains, because a. in the hills the atmospheric pressure is lower than that in the plains and therefore water boils at a temperature lower than 100 deg C causing an increase in cooking time b. due to a lower pressure on the hills, the water boils at a temperature higher than 100 deg C and therefore water takes longer to boil c. in the hills the atmospheric density is low and therefore a lot of heat is lost to the atmosphere d. in the hills the humidity is high and therefore a lot of heat is absorbed by the atmosphere leaving very little heat for cooking

Answer 43

a. in the hills the atmospheric pressure is lower than that in the plains and therefore water boils at a temperature lower than 100 deg C causing an increase in cooking time

Question 44

Intensity of sound at a point is _____________ its distance from the source a. directly proportional to b. inversely proportional to c. directly proportional to square of d. inversely proportional to square of

Answer 44

d. inversely proportional to square of

Question 45

Of the four locations mentioned below the highest inside temperature will be attained in the pressure cooker operated with the pressure valve open. a. at sea level b. at the top of Mt. Everest c. at a place below sea level d. in an aeroplane flying at a height of 10km with inside pressure maintained at the sea level

Answer 45

c. at a place below sea level

Question 46

Mercury is commonly used as a thermodynamic fluid rather than water because a. specific heat of mercury is less than water b. specific heat of mercury is more than water c. mercury has greater visibility than water d. density of mercury is more than the water

Answer 46

c. mercury has greater visibility than water