Physics: MCQ Test (50 questions)

Question 1 of 50

Why are white clothes cooler than black clothes?

Aabsorb all light that reaches them
BThey reflect whatever light reaches them.
Cdoes not allow light to penetrate
DCompletely cools the sunlight

Question 2 of 50

When a ray of light passes from a rarer medium to a denser medium, it-

Amoves in a straight direction
Bbends towards the normal.
Cmoves away from the normal
Dnone of these

Question 3 of 50

The intensity of sound of ordinary conversation is-

A20-30dB
B30-40 dB
C50-60dB
D90-100 dB

Question 4 of 50

When an object is taken from the Earth to the Moon, then-

Ahis weight increases
Bhis weight decreases
Cthere is no change in its weight
DIt becomes completely weightless,

Question 5 of 50

What is the purpose of a thermostat?

AMeasuring Temperature
Braising the temperature
CKeeping the temperature stable
Dconverting heat into electricity

Question 6 of 50

Who invented the helicopter?

ACockerel
BBriquettes
COtis
DFrank Whitley

Question 7 of 50

Which instrument is used to measure atmospheric pressure?

AHydrometer
Bbarometer
CManometer
DHygrometer

Question 8 of 50

A stone is placed at the bottom of a cup filled with water. The apparent depth of the north is-

Aequal to its actual depth
BOrder by its actual depth
COrder by its actual depth
DEither A or C has one

Question 9 of 50

The focal length of a convex lens is 0.2 m. Its power will be-

A+2 D
B2D
C4D
D+5 D

Question 10 of 50

The phenomenon associated with forming a three-dimensional image by the interference of two light rays emanating from a laser or any other coherent light source is called –

Aoptical photography
BX-ray photography
CRadiation Illustration
DHolography

Question 11 of 50

Which of the following colours of light diverges the least through a prism?

ARed
BGreen
CPurple
DYellow

Question 12 of 50

Which part of a photographic camera acts like the retina of the eye?

Alight hole
Bshutter
Clens
DMovie

Question 13 of 50

When two loudspeakers are used simultaneously at a place, a listener sitting at a particular place cannot hear their sound. This is because:

Areflection
Binterference
CRefraction
Dresonance

Question 14 of 50

A person pushes a wall but fails to displace it, then he does-

ANo work whatsoever
Bnegative work
Cpositive but not maximum work
DMaximum work

Question 15 of 50

Which lens is used in the spectacles of a person suffering from farsightedness?

Aconvex lens
Bconcave lens
Cflat lens
Dplano-concave lens

Question 16 of 50

When hot water is poured over a thick glass tumbler, it shatters. What is the reason for this?

ASuddenly the glass expands.
BSuddenly the glass shrinks.
CThe water evaporates.
DGlass is chemically repelled by water.

Question 17 of 50

The angle which a magnetic needle freely suspended at its centre of gravity makes with the horizontal is called-

Abowing angle
Bsubluxation angle
CHorizontal angle
DNone of these

Question 18 of 50

The magnetic effect of electric current was first observed in-

Aby Henry
Bby Ostend
Cby Faraday
DBy Volta

Question 19 of 50

How much is a decalitre?

A10 kilometers
B10 liters
C10 centilitres
D100 liters

Question 20 of 50

Nichrome wire is used as a heating element because-

AIts strings can be pulled
BIts specific resistance is high
CDoes not form oxide when heated red hot
DBecause of both b and c above

Question 21 of 50

The inventor of the electric bulb is-

AJ.L. Baird
BJ.B. Reyes
CThomas Alva Edison
DMarconi

Question 22 of 50

Earth is used in electrical equipment for-

Ato reduce expenses
BBecause the appliances operate on 3-phase
CFor safety
DAs a fuse

Question 23 of 50

When a short circuit condition occurs, the current in the circuit-

Abecomes zero
Bremains stable
Cgrows sufficiently
Dchanges randomly

Question 24 of 50

Who discovered the 'Law of Floating' principle?

ANewton
BWright Brothers
CGalileo
DArchimedes

Question 25 of 50

Why does the atmosphere turn red at sunrise and sunset?

Arefraction of light
Breflection of light
Cdispersion of light
Dscattering of light

Question 26 of 50

Who discovered the positron?

ARutherford
BThomson
CChadwick
DAnderson

Question 27 of 50

The standard sound level for humans is-

A90dB
B60dB
C120 dR
D100 aB

Question 28 of 50

LIST (Visual Defects) List-II (Treatment) A. Near vision defects 1.Convex lens B. Far vision defects 2.Bifocal lens C. Zara vision defects 3.Cylindrical lens D. Non-concavity 4. Concave lens

AABCD 1 2 3 4
BABCD 1 4 3 2
CABCD 4 3 2 1
DABCD 4 1 2 3

Question 29 of 50

What should be the time interval between the original sound and the echo to hear an echo?

Aequal to 1/10 second
Bless than 1/10-second
Cmore than 1/10-second
DNone of these.

Question 30 of 50

Farsightedness in old age is a defect in which the lens-

Aloses its elasticity
Bbecomes more transparent.
Cbecomes much smaller
Dbecomes much smaller

Question 31 of 50

Echo is produced due to the _______ of waves.

ARefraction
BAbsorption
Creflection
DDiffraction

Question 32 of 50

On what does the specific heat of an object depend?

Aon the mass of the body
Bon the heat provided to the body
Con the mass of the body
Dat the body temperature

Question 33 of 50

The rate at which an object cools is directly proportional to the temperature difference between the object and the medium surrounding it. This law is:

ANewton's law of cooling
BStefan's radiation law
CKirchhoff's law
Dzero point law of thermodynamics

Question 34 of 50

A tennis ball bounces higher on a hill than on a plain because-

AThe air pressure is relatively low in the mountains.
BThe ball becomes lighter on the mountains
CThe acceleration due to gravity of the Earth decreases in the mountains.
Dnone of the above

Question 35 of 50

The MCB which cuts off the power supply in case of a short circuit works by—

AOn the magnetic effect of current
Belectroplating effect of current
COn the chemical effects of current
DOn the heating effect of current

Question 36 of 50

If the door of the refrigerator kept in the room is left open-

AThe room will cool down to the temperature inside the refrigerator.
BThe room will cool to a temperature higher than the inside of the refrigerator
CThe room will gradually heat up
DThe temperature of the air in the room will remain unchanged.

Question 37 of 50

body will remain at rest unless acted upon by an external force. Whose statement is this?

ANewton
BEinstein
CArchimedes
DGalileo

Question 38 of 50

Which of the following statements is not correct for light rays?

Alight travels at different speeds in different media
BLight travels in air at a speed of about 300 million meters per second
CAs light leaves the surface of water and enters the air, its speed slows down
DAs light leaves the glass surface and enters the air, its speed increases

Question 39 of 50

The telescope was invented by-

AGalileo
BGutenberg
CEdison
Dreceptive well

Question 40 of 50

On what principle does a rocket work?

ANewton's third law
BNewton's first law
CNewton's second law
DArchimedes' principle

Question 41 of 50

What is the instrument called that measures the intensity of the sun's rays?

AAstrometer
BCrescograph
CActiometer
Dbarometer

Question 42 of 50

What is a flight recorder technically called?

Aaltimeter
BDark Box
Cblind box
Dblack box

Question 43 of 50

The heat required to convert a unit mass of a solid substance from solid to liquid at its melting point is called-

Amelting point of a solid
Bboiling point of a solid
Clatent heat of fusion of a solid
Devaporation

Question 44 of 50

Temporary magnets are made from-

Aof steel
Bsoft iron
Ccopper
DSilver

Question 45 of 50

By what is alternating current converted into direct current?

AFilter
BRectifier
CMotor
DTransformers

Question 46 of 50

Isotopes are atoms of the same element that have

ASame atomic weight but different atomic number
BDifferent atomic weights but same atomic number
CBoth atomic mass and atomic number are the same.
Dnone of the above

Question 47 of 50

Which of the following is not a semiconductor?

AGermanium
BSilicon
CSelenium
DArsenic

Question 48 of 50

The mass of an object is 100 kg (gravitational force g = 10 ms). If the gravitational acceleration on the moon is , then the mass of the object on the moon will be-

A100 /6 kg
B60 kg
C100 kg
D600 kg

Question 49 of 50

Why do bicycle tubes burst mostly in summer?

AThe tube bursts due to heat.
BRubber becomes very weak due to heat.
CHeat causes the rubber to harden and not expand to accommodate air.
Dnone of the above

Question 50 of 50

Due to which force does a horse pulling a cart move forward?

Athe force exerted by the cart on the horse
Bthe force exerted by the horse on the cart
Cthe force exerted by the horse on the earth with its feet
Dthe force exerted by the earth on the horse's feet