# Railway Physics Quiz for RRB ALP Exam |RRB | 10th JANUARY 2019

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. A cut diamond shines brilliantly due to-

(a) Total internal reflection

(b) Absorption of light

(c) Some inherent property

(d) Its molecular structure

Q2. Which of the following is used to take 3-dimentional pictures-

(a) Photography

(b) Holography

(d) None of the above

Q3. An astronaut sees the colour of the sky as-

(a) Blue

(b) White

(c) Black

(d) Red

Q4. When a piece of ice floating in a glass of water melts, the level of water will:

(a) Fall

(b) Rise

(c) Remain same

(d) Fall or rise depends on the temperature of water

Q5. Satellite is kept moving in its orbit around the Earth; it is due to

(a) Centrifugal force

(b) Centripetal force

(c) Gravitational force or lack of it

(d) Some other forces

Q6. Earth’s escape velocity is-

(a) 15.0km/sec.

(b) 21.1km/sec.

(c) 7.0km/sec

(d) 11.2km/sec

Q7. Which one of the following colours is seen in the middle of a Rainbow?

(a) Blue

(b) Green

(c) Red

(d) Yellow

Q8. In which direction the rainbow is seen at 12 noon?

(a) In the West

(b) In the South

(c) In the East

(d) It cannot be seen

Q9. Colour in a colour television is produced by a combination of three basic colours, they are:-

(a) Red, blue and orange

(b) Red, green and blue

(c) Red, yellow and green

(d) Red, green and brown

Q10. The velocity of wind is measured by:

(a) Barometer

(b) Anemometer

(c) Hydrometer

(d) Wind Vane

## Solution

Ans.1.(a)

Exp. The refractive index of diamond is very high. Diamond achieves brilliance partially from total internal refraction. It has been cut or designed in such a way that if light enters into it, incident light strikes many of the internal surfaces.

Ans.2.(b)

Exp. Holography is a technique of producing a three-dimensional image of an object. Holography can work with sound, light or any wavelength. It is also been used for three-dimensional natural films.

Ans.3.(c)

Exp. The colour of the sky for an astronaut is black. It is because of the fact that in the space there is no atmosphere. Hence light doesn’t get scattered at all. In addition to this, in space, there are no air particles against which the sunlight can strike, get reflected or scattered. Hence, astronaut see everything black.

Ans.4.(c)

Exp. We know that the mass of liquid displaced by the floating ice equals to the mass of the object. That’s why the ice caps float on water. Similarly, when an ice cube melts in a glass of water, the water level does not change as the melted water will occupy exactly the same amount of space as the ice under the water level previously occupied.

Ans.5.(b)

Exp.Centripetal force is a real force that counteracts the centrifugal force and prevents the object from “flying out,” keeping it moving instead with a uniform speed along a circular path.

Ans.6.(d)

Exp. The escape velocity of earth is 11.2 km/sec.

Ans.7.(b)

Exp. The correct order of colors of the rainbow is Red, Orange, Yellow, Green, Blue, Indigo and Violet. Thus it is clear that ‘Green’ Color is seen in the middle of Rainbow (VIBGYOR).

Ans.8.(d)

Exp. A rainbow is located opposite to the sun; this explains why rainbow is not seen at 12 noon with the sun overhead.

Ans.9.(b)

Exp. The cathode ray tube (CRT), which is used in colour television uses three different phosphors which emit red, green and blue light respectively. They are packed together in stripes or clusters called “triads”.

Ans.10.(b)

Exp. An anemometer is a device for measuring wind speed .

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