Exercise 1

Question 1 :

Radiocarbon is produced in the atmosphere as a result of


A). collision between fast neutrons and nitrogen nuclei present in the atmosphere
B). action of ultraviolet light from the sun on atmospheric oxygen
C). action of solar radiations particularly cosmic rays on carbon dioxide present in the atmosphere
D). lightning discharge in atmosphere
Answer : Option A

Question 2 :

It is easier to roll a stone up a sloping road than to lift it vertical upwards because


A). work done in rolling is more than in lifting
B). work done in lifting the stone is equal to rolling it
C). work done in both is same but the rate of doing work is less in rolling
D). work done in rolling a stone is less than in lifting it
Answer : Option D

Question 3 :

The absorption of ink by blotting paper involves


A). viscosity of ink
B). capillary action phenomenon
C). diffusion of ink through the blotting
D). siphon action
Answer : Option B

Question 4 :

Siphon will fail to work if


A). the densities of the liquid in the two vessels are equal
B). the level of the liquid in the two vessels are at the same height
C). both its limbs are of unequal length
D). the temperature of the liquids in the two vessels are the same
Answer : Option B

Question 5 :

Large transformers, when used for some time, become very hot and are cooled by circulating oil. The heating of the transformer is due to


A). the heating effect of current alone
B). hysteresis loss alone
C). both the heating effect of current and hysteresis loss
D). intense sunlight at noon
Answer : Option C

Question 6 :

Nuclear sizes are expressed in a unit named


A). Fermi
B). angstrom
C). newton
D). tesla
Answer : Option A

Explanation :

Fermi - A unit of length equal to 10-15 meter (one femtometer), used in nuclear physics. It is similar to the diameter of a proton.


Question 7 :

Light year is a unit of


A). time
B). distance
C). light
D). intensity of light
Answer : Option B

Question 8 :

Mirage is due to


A). unequal heating of different parts of the 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 : Option A

Question 9 :

Light from the Sun reaches us in nearly


A). 2 minutes
B). 4 minutes
C). 8 minutes
D). 16 minutes
Answer : Option C

Question 10 :

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 : Option B

Question 11 :

Pa(Pascal) is the unit for


A). thrust
B). pressure
C). frequency
D). conductivity
Answer : Option B

Question 12 :

Planets do not twinkle because


A). they emit light of a constant intensity
B). their distance from the earth does not change with time
C). they are very far away from the earth resulting in decrease in intensity of light
D). they are nearer to earth and hence we receive a greater amount of light and, therefore minor variations in the intensity are not noticeable
Answer : Option D

Question 13 :

Metals are good conductors of electricity because


A). they contain free electrons
B). the atoms are lightly packed
C). they have high melting point
D). All of the above
Answer : Option A

Question 14 :

Let a thin capillary tube be replaced with another tube of insufficient length then, we find water


A). will overflow
B). will not rise
C). depressed
D). change its meniscus
Answer : Option B

Question 15 :

Out of the following pairs, choose the pair in which the physical quantities do not have identical dimension?


A). Pressure and Young's modules
B). Planck's constant and Angular momentum
C). Impulse and moment of force
D). Force and rate of change of linear momentum
Answer : Option C

Question 16 :

If two bodies of different masses, initially at rest, are acted upon by the same force for the same time, then the both bodies acquire the same


A). velocity
B). momentum
C). acceleration
D). kinetic energy
Answer : Option B

Question 17 :

Pick out the scalar quantity


A). force
B). pressure
C). velocity
D). acceleration
Answer : Option B

Question 18 :

Rectifiers are used to convert


A). Direct current to Alternating current
B). Alternating current to Direct current
C). high voltage to low voltage
D). low voltage to high voltage
Answer : Option B

Question 19 :

out of the following, which is not emitted by radioactive substance?


A). Electrons
B). Electromagnetic radiations
C). Alpha particles
D). Neutrons
Answer : Option D

Question 20 :

Sound waves in air are


A). transverse
B). longitudinal
C). electromagnetic
D). polarised
Answer : Option B

Question 21 :

Magnetism at the centre of a bar magnet is


A). minimum
B). maximum
C). zero
D). minimum or maximum
Answer : Option C

Question 22 :

It is more difficult to walk on a sandy road than on a concrete road because


A). sand is soft and concreter is hard
B). the friction between sand and feet is less than that between concrete and feet
C). the friction between sand and feet is more than that between concrete and feet
D). the sand is grainy but concrete is smooth
Answer : Option B

Question 23 :

Find the maximum velocity for the overturn of a car moving on a circular track of radius 100 m. The co-efficient of friction between the road and tyre is 0.2


A). 0.14 m/s
B). 140 m/s
C). 1.4 km/s
D). 14 m/s
Answer : Option D

Question 24 :

Of the following properties of a wave, the one that is independent of the other is its


A). amplitude
B). velocity
C). wavelength
D). frequency
Answer : Option A

Question 25 :

Lux is the SI unit of


A). intensity of illumination
B). luminous efficiency
C). luminous flux
D). luminous intensity
Answer : Option A

Explanation :

The SI unit of intensity of illumination (illuminance) is the lux. An illuminance of 1.0 lux is produced by 1.0 lumen of light shining on an area of 1.0 m^2.