# Railway Physics Quiz for RRB ALP Exam |RRB | 22nd December 2018

Get daily topic-wise Railway Quiz Questions and answers for various RRB exams like NTPC, JE, ALP, Group C and D. Free section-wise Indian railway quiz for RRB Exam.

Q1. Knot is measure of

(a) The speed of ship

(b) The curvature of spherical objects

(d) Intensity of earthquake shock

Q2. The dimension of which of the following is the same as that of impulse?

(a) Volume

(b) Momentum

(c) Torque

(d) Change in the rate of momentum

Q3. Which one of the following statements is not true about cosmic rays ?

(a) They are electromagnetic waves

(b) They have very short wavelength

(c) They are made of highly energetic charged particles.

(d) They originate from the sum

Q4. What is the distance between two successive crests or successive troughs called ?

(a) Amplitude

(b) Wavelength

(c) Frequency

(d) None of these

Q5. Gravitational force is maximum at which of the following place?

(a) At equator

(b) At tropic of cancer

(c) At tropic of Capricorn

(d) At poles

Q6. There is no atmosphere on the moon because

(a) It is closer ot the earth

(b) It revolves round the earth

(c) It gets light from the sun

(d) the value of escape velocity on the surface of the moon is small

Q7. The dimensions of universal gravitational constant are

(a) M2 L2 T–2

(b) M–1 L3 T–2

(c) M L–1 T–2

(d) M L2 T–2

Q8. Two stones of different masses are dropped simultaneously from the top of a building

(a) smaller stone reaches the ground earlier

(b) larger stone reaches the ground earlier

(c) both the stones reach the ground at the same time

(d) depends on the composition of the stone

Q9. What should a person on a freely rotating turn table do to decrease his (angular) speed?

(a) Bring his hands together

(b) Raise his hands up

(d) Sit down with raised hands

Q10. A boy sitting in an open car moving with the constant speed throws a ball straight up into the air. The ball falls

(a) behind him

(b) in front of him

(c) into his hand

(d) None of these

## Solutions

Ans.1.(a)

Exp. A knot is one nautical mile per hour (1 knot = 1.15 miles per hour ). The term knot dates from the 17th century, when sailors measured the speed of their ship by using a device called a “common log.” This device was a coil of rope with uniformly spaced knots, attached to a piece of wood shaped like a slice of pie.

Ans.2.(b)

Exp.  Dimensional formula for impulse and momentum are  same  MLT-1.

Ans.3.(a)

Exp. Cosmic rays are not the part of electromagnetic spectrum. They are immensely high-energy radiation waves, mainly originating outside the solar system.

Ans.4.(b)

Exp.  Wavelength means the distance measured in the direction of a wave from any given point to the next point in the same phase, as from crest to crest. The distance between two successive crests or two successive troughs is the wavelength for a transverse wave.

Ans.5.(d)

Exp. The value of Gravitational Force range from a minimum of 9.78 metre per second squared at the Equator to a maximum of 9.83 metre per second squared at the poles. Hence Gravitational Force is maximum on polls.

Ans.6.(d)

Exp.  Moon has no atmosphere because the value of acceleration due to gravity ‘g’ on surface of moon is small. Therefore, the value of escape velocity on the surface of the moon is small . The molecules of the atmospheric gases on the surface of the moon have thermal velocities greater than the escape velocity. That is why all the molecules of gases have escaped and there is no atmosphere on moon.

Ans.7.(b)

Exp. Dimensional Formula of Universal Constant of Gravitation = M–1 L3 T–2

Ans.8.(c)

Exp.  Both stones reach on the ground in the same interval of time and also with same velocity because earth attract all the object in the centre with same acceleration 9.8m/s.

Ans.9.(c)

Exp.  A person on a freely rotating turn table do to decrease his (angular) speed on Spread his hands outwards.

Ans.10.(c)

Exp. Since the velocity is constant, the horizontal component of velocity for the car and the ball are the same. Therefore, they cover equal horizontal distances in the same time interval. Therefore the ball will land in the into his hand.

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