General Science Physics MCQ-6

It is easier to swim in a sea water than in ordinary water because

(A) sea water contains salt
(B) atmospheric pressure is highest at the sea level
(C) density of sea water is less than that of ordinary water
(D) density of sea water is higher than that of ordinary water

The modulus of rigidity of a liquid is

(A) zero
(B) infinite
(C) 1
(D) None of these

SONAR is based on the principle of

(A) resonance
(B) reverberation
(C) echo
(D) None of these

For a body float in a liquid with some portion outside, the weight of the liquid displaced by the fully immersed body

(A) should be more than the weight of the body
(B) should be equal to the weight of the body
(C) should be less than the weight of the body
(D) None of the above

Consider the following statements and select the correct code
1. For a given stress, the strain produced in glass is much less than that in rubber,
2. In plastic materials, the force of cohesion are very small.
3. Elastic limit is the smallest stress, which results in permanent distortion.
Codes

(A) 1, 2 and 3
(B) 1 and 2
(C) 2 and 3
(D) 1 and 3

Polarization in electromagnetic wave is caused by

(A) refraction
(B) reflection
(C) transverse nature of electromagnetic waves
(D) longitudinal nature of electromagnetic waves

Two pieces of different metals, when completely immersed in water, experience equal up thrust, then

(A) both pieces have same density
(B) both pieces have equal volume
(C) both pieces have equal weight in air
(D) None of the above

Consider the following statements
1. Greater the value of Young’s modulus of a material, larger is its elasticity.
2. Steel is more elastic than copper.
Which of the statement(s) given above is/are correct?

(A) Only 1
(B) Only 2
(C) Both 1 and 2
(D) Neither 1 nor 2

What frequency range of EM waves are used for commercial FM radio?

(A) 88 MHz to 108 MHz
(B) 88 GHz to 108 GHz
(C) 88 kHz to 108 kHz
(D) None of the above

A steel ball is floating in a beaker containing mercury. If some water is poured in the breaker, the steel ball will

(A) move up
(B) move down
(C) continue its position
(D) execute vertical oscillation

Assertion (A) The solids are more elastic and gases are least elastic.
Reason (R) It is so because for the given stress applied the gases are more compressible than that of solids.

(A) Both A and R are true and R is the correct explanation of A
(B) Both A and R are true and R is not the correct explanation of A
(C) A is true but R is false
(D) A is false but R is true

Why is sound heard with more intensity through C02 than through the air?

(A) Density of C0 2 is more than that of air
(B) Density of CO 2 is less than that of air
(C) Air is a bad conductor of heat
(D) C0 2 is a compound but air is a mixture of gases

An inflated balloon is floating on the surface of water. It is pushed so as to submerge completely and then released. It will

(A) sink to the bottom
(B) come back to its earlier position
(C) remain submerged at the same place
(D) first sink to the bottom and then come up

Consider the following statements
1. Young’s modulus of elasticity is defined as the ratio of normal stress to the longitudinal strain within the elastic limit.
2. Bulk modulus of elasticity is defined as the ratio of normal stress to the volumetric strain, within the elastic limit.
Which of the statement(s) given above is/are correct?

(A) Only 1
(B) Only 2
(C) Both 1 and 2
(D) Neither 1 nor 2

The wavelength of X-rays is of the order of

(A) 1 mm
(B) 1 cm
(C) 1 micron
(D) 1 angstrom

A body is just floating in a liquid if the body is slightly pressed down and released. It will

(A) start oscillating
(B) sink to the bottom
(C) come back to the same position immediately
(D) come back to the same position stable

Consider the following statements
1. The SI unit of Young’s modulus of elasticity is Pascal.
2. Young’s modulus is involved in solids only.
3. The SI unit of Bulk modulus of elasticity is or Pascal.
4. Bulk modulus is involved in solids ,Liquids and gases.
Which of the statements given above are correct?

(A) 1, 2 and 3
(B) 2, 3 and 4
(C) 1, 3 and 4
(D) 1, 2, 3 and 4