Physics (Part-I) (Railway)

Total Questions: 50

1. The instrument used to regulate temperature to a particular degree is called: [RRB NTPC CBT Stage-I Exam, 30.03.2016 Shift-III]

(A) Thermostat

(B) Thermometer

(D) Thermocouple

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

Correct Answer: (2) A

Solution:Thermostat is an instrument used to regulate temperature to a particular degree. It senses the temperature of a system so that the system's temperature is maintained near a desired setpoint. A thermostat can often be the main control unit for a heating or cooling system.

2. Evaporation of a liquid to absorb heat is the principle used by a- [RRB NTPC CBT Stage-1 Exam, 31.03.2016 Shift-I]

(A) Microwave Oven

(B) Refrigerator

(D) Electric Kettle

(1) C
(2) D
(4) B
(4) B

Correct Answer: (4) B

Solution:A refrigerator uses the evaporation of a liquid refrigerant to absorb heat from the food compartment. The refrigeration cycle is actually about removing heat from the environment rather than introducing cold air into it. In the refrigeration cycle, refrigerant is evaporated and liquefied as it flows through tubes as a means to transfer heat.

3. Water droplets cause rainbow due to- [RRB NTPC CBT Stage-I Exam, 31.03.2016 Shift-I]

(A) Reflection of sunlight

(B) Refraction of sunlight

(D) Diffusion of sunlight

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

Correct Answer: (4) C

Solution:Rainbows result from a series of physical phenomena reflection, refraction, dispersion and total internal reflection. The occurrence of each of these is due to the interaction of light with air and water and the boundaries between them. Rainbows result from refraction of sunlight in falling water droplets plus reflection of the light from the back of the droplet.

4. The abbreviation LHC stands for which machine? [RRB NTPC CBT Stage-1 Exam, 19.04.2016 Shift-I]

(A) Large Hadron Collider

(B) Long Heavy Collider

(D) Light Heat Collider

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

Correct Answer: (2) A

Solution:LHC stands for Large Hadron Collider. It is the world's largest and most powerful particle collider and the largest single machine in the world. It was built by the European Organization for Nuclear Research (CERN) between 1998 and 2008 in collaboration with over 10.000 scientists and engineers from over 100 countries.

5. The value of universal gravitational constant (G) was determined by: [RRB ALP & Technician Exam, 09.08.2018 Shift-III)]

(1) Henry Cavendish
(2) Antonie L. Lavoisier
(3) Isaac Newton
(4) John Dalton

Correct Answer: (1) Henry Cavendish

Solution:The gravitational constant is the proportionality constant used in Newton's Law of Universal Gravitation. and is commonly denoted by G. The first person who successfully measured it was the English physicist, Henry Cavendish, who measured the very tiny force between two lead masses by using a very sensitive torsion balance.

6. A raised hammer possesses: [RRB ALP & Technician Exam, 09.08.2018 Shift-III]

(1) Kinetic energy
(2) Mechanical energy
(3) Muscular energy
(4) Potential energy

Correct Answer: (4) Potential energy

Solution:The energy possessed by a raised hammer is potential energy. Once the hammer hits the nail with a velocity, the whole potential energy is converted into kinetic energy according to the law of conservation of energy.

7. A person holding a pen in his left hand sees his reflection in the mirror holding the pen in his right hand. This is due to which of the following phenomena? [RRB ALP & Technician Exam, 09.08.2018 Shift-III]

(1) Diffused reflection
(2) Total internal reflection
(3) Lateral inversion
(4) Refraction

Correct Answer: (3) Lateral inversion

Solution:The phenomenon due to which left-hand side of an object appears as righthand side of the object and vice versa is called lateral inversion. It is due to direction that light follows when it strikes a reflecting surface, generally а mігтог.

8. The kinetic energy of a ball weighing 0.5 kg moving with a velocity of 4 m/s will be: [RRB ALP & Technician Exam, 10.08.2018 Shift-I]

(1) 12 J
(2) 8 J
(3) 4 J
(4) 16 J

Correct Answer: (3) 4 J

Solution:The Kinetic energy is the energy that an object has due to its motion. It is expressed

as K.E. = 1/2 mv², where m is

mass and v is the velocity of the object.

So, according to the question, the kinetic energy of the object

= 1/2 16 × 0.5 × 4²= 16/4 = 4 J

9. Which is the form of energy that does NOT occur while riding a bicycle? [RRB ALP & Technician Exam, 10.08.2018 Shift-I]

(1) Chemical energy
(2) Heat energy
(3) Mechanical energy
(4) Kinetic energy

Correct Answer: (1) Chemical energy

Solution:Riding a bicycle involves the conversion of muscular energy (chemical energy) into mechanical energy, the sum of the kinetic energy and potential energy. Besides, friction of the bicycle against the ground surface also produces heat and sound energy.

10. When a ray of light travels from a denser medium to a rarer medium, it bends: [RRB ALP & Technician Exam, 10.08.2018 Shift-I]

(1) towards the normals and slows down
(2) away from the normal and slows down
(3) towards the normal and speeds up
(4) away from the normal and speeds up

Correct Answer: (4) away from the normal and speeds up

Solution:When a ray of light travels from a denser medium to a rarer medium, it bends away from the normal fat the point of incidence). The speed of light is less in a denser medium. Thus, ray of light travelling from a denser medium to a rarer medium speeds up and bends way from the normal.

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