Exercise 3

Question 1 :

Out of the following pairs, which one does not have identical dimension?

A). Moment of inertia and moment of a force
B). Work and Torque
C). Angular momentum and Planck's constant
D). Impulse and Momentum
Answer : Option A

Question 2 :

Mercury is commonly used as a thermometric 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 : Option C

Question 3 :

Optical fibre works on the

A). principle of refraction
B). total internal reflection
C). scattering
D). interference
Answer : Option B

Question 4 :

Light from the star, Alpha Centauri, which is nearest to the earth after the sun, reaches the earth in

A). 4.2 seconds
B). 42 seconds
C). 4.2 years
D). 42 years
Answer : Option C

Question 5 :

Supersonic plane fly with the speed

A). less than the speed of sound
B). of sound
C). greater than the speed of sound
D). of light
Answer : Option C

Question 6 :

Mach number is used in connection with the speed of

A). sound
B). aircraft
C). spacecraft
D). ships
Answer : Option B

Question 7 :

On a stationary sail boat, air is blown from a fan attached to the boat. The boat

A). moves in opposite direction in which the air is blown
B). does not move
C). moves in the same direction in which air blows
D). spins around
Answer : Option B

Question 8 :

Rainbow is due to

A). absorption of sunlight in minute water droplets
B). diffusion of sunlight through water droplets
C). ionisation of water deposits
D). refraction and reflection of sunlight by water droplets
Answer : Option D

Question 9 :

Stars which appear single to the naked eye but are double when seen through a telescope are

A). novas and supernovas
B). binaries
C). asteroids
D). quasars
Answer : Option B

Question 10 :

ML2T-2 is the dimensional formula for

A). moment of inertia
B). pressure
C). elasticity
D). couple acting on a body
Answer : Option D

Question 11 :

Solar eclipse will take place when

A). the sun is between the moon and the earth
B). the earth is between the moon and the sun
C). the moon is between the sun and the earth
D). the moon does not lie on the line joining the sun and the earth
Answer : Option C

Question 12 :

Isotopes of an element contain

A). the same number of protons but different number of neutrons
B). the same number of neutrons but different number of protons
C). equal number of protons and electrons
D). equal number of nucleons
Answer : Option A

Question 13 :

One watt-hour is equivalent to

A). 6.3 x 103 J
B). 6.3 x 10-7 J
C). 3.6 x 103 J
D). 3.6 x 10-3 J
Answer : Option C

Question 14 :

Sir C.V. Raman was awarded Nobel Prize for his work connected with which of the following phenomenon of radiation?

A). Scattering
B). Diffraction
C). Interference
D). Polarization
Answer : Option A

Question 15 :

In which of the following industries is mica as a raw material?

A). Cement
B). Glass and Pottery
C). Iron and Steel
D). Electrical
Answer : Option D

Question 16 :

Radiocarbon dating technique is used to estimate the age of

A). rocks
B). monuments
C). soil
D). fossils
Answer : Option D

Question 17 :

Identify the vector quantity from the following

A). Heat
B). Angular momentum
C). Time
D). Work
Answer : Option B

Question 18 :

Large astronomical telescopes always use as objective

A). lens
B). mirror
C). combinations of lenses
D). None of the above
Answer : Option C

Question 19 :

One should not connect a number of electrical appliances to the same power socket because

A). this can damage the appliances due to overloading
B). this can damage the domestic wiring due to overloading
C). this can damage the electrical meter
D). the appliance will not get full voltage
Answer : Option B

Question 20 :

Rainbow is produced when sunlight fall on drops of rain. Which of the following physical phenomena are responsible for this? Diffusion Refraction Internal reflection

A). I, II and III
B). I and II
C). II and III
D). I and III
Answer : Option C

Question 21 :

Natural radioactivity was discovered by

A). Marie Curie
B). Ernest Rutherfor
C). Henri Becquerel
D). Enrico Fermi
Answer : Option C

Question 22 :

Planets are

A). luminous heavenly bodies revolving around a star
B). non-luminous heavenly bodies
C). luminous heavenly bodies that twinkle
D). luminous heavenly bodies that do not twinkle
Answer : Option B

Question 23 :

One nanometer is equal to

A). 10-6m
B). 10-8m
C). 10-9m
D). 10-5m
Answer : Option C

Question 24 :

Mica is used in electrical appliances such as electric iron because mica is

A). a good conductor of heat but a bad conductor of electricity
B). a bad conductor of heat but a good conductor of electricity
C). a good conductor of heat as well as electricity
D). a bad conductor of heat as well as electricity
Answer : Option A

Question 25 :

It is easier to roll a barrel full of coal tar than to pull it because

A). the full weight of the barrel comes into play when it is pulled
B). the rolling friction is much less than the sliding friction
C). more surface area of the barrel is in contact with the road when it is pulled
D). coal tar is a liquid and it flows in the barrel when it is rolled
Answer : Option B

Question 26 :

Minimum number of unequal vectors which can give zero resultant are

A). two
B). three
C). four
D). more than four
Answer : Option B

Question 27 :

Intensity of sound has

A). an object existence
B). a subject existence
C). no existence
D). both subjective and objective existence
Answer : Option A

Question 28 :

Rain is falling vertically downwards. To a man running east-wards, the rain will appear to be coming from

A). east
B). west
C). northeast
D). southeast
Answer : Option A

Question 29 :

An aeroplane is flying horizontally with a velocity of 600 km/h and at a height of 1960 m. When it is vertically at a point A on the ground a bomb is released from it. The bomb strikes the ground at point B. The distance AB is

A). 1200 m
B). 0.33 km
C). 3.33 km
D). 33 km
Answer : Option C