Physics (Part-III) (Railway)

Total Questions: 50

1. According to the energy theory, the possible demand of electricity (8,00,000) in which year? [RRB RPF/RPSF SI Exam, 06.01.2019 Shift-III]

(1) 2021-2022
(2) 2041-2042
(3) 2031-2032
(4) 2051-2052

Correct Answer: (3) 2031-2032

Solution:Government has prepared an Integrated Energy Policy (IEP), to address the issue of long-term energy policy in the country. As per the IEP, , India's primary energy use is projected to expand to deliver a sustained growth rate of 9% through 2031-32 even after allowing for substantial reduction in energy intensity.

2. What is the formula for pressure? [RRB RPF/RPSF SI Exam, 10.01.2019 Shift-II]

(1) Volume/area
(2) Force/area
(3) Force/Volume
(4) Force/time

Correct Answer: (2) Force/area

Solution:Pressure is defined as the physical force exerted on an object. The force applied is perpendicular to the surface of objects per unit area. The basic formula for pressure is F/A (Force per unit area). Unit of pressure is Pascals (Pa).

3. The process of converting into gas is known as: [RRB RPF/RPSF SI Exam, 10.01.2019 Shift-II]

(1) Rain
(2) Vaporization
(3) The process of creating pressure
(4) Summarize

Correct Answer: (2) Vaporization

Solution:Vaporization can be defined as the process in which liquid state changes into the vapour state. As a result of an increase in temperature, the kinetic energy of the molecules increases. Due to the Increases in kinetic energy, the force of attraction between the molecules reduces. As a result. they escape into the surrounding in the form of vapours. This process involves the consumption of heat energy.

4. Formula of finding Acceleration is- [RRB RPF/RPSF SI Exam, 10.01.2019 Shift-III]

(1) Velocity x Time
(2) Time/Velocity
(3) Work/Time
(4) Velocity/Time

Correct Answer: (4) Velocity/Time

Solution:Acceleration is the rate of change of velocity with time. It is a vector quantity. If the velocity of the object increases with time, its acceleration Increases. If the velocity of an object decreases with time, its acceleration is negative. Acceleration = Change in velocity/time taken.

5. Prefix of multiple 10-²¹ in Sl system is________. [RRB RPF/RPSF SI Exam, 10.01.2019 Shift-III]

(1) Exa
(2) Zepto
(3) Zita
(4) Femto

Correct Answer: (2) Zepto

Solution:Zepto (unit symbol z) is a unit prefix in the metric system denoting a factor of 10-²¹. Adopted in 1991, it comes from the Latin septem, meaning "seven", since it is equal to 1000-⁷.

6. Who has propagated the Principale of Light wave: [RRB RPF/RPSF SI Exam, 10.01.2019 Shift-III]

(1) Paul Dirak
(2) Robert A. Milican
(3) Cristian Huygens
(4) Homi Jahangir Bhabha

Correct Answer: (3) Cristian Huygens

Solution:In 1678, Dutch physicist, Christia in Huygens, believed that light was made up of waves vibrating up and down perpendicular to the direction of the light travels, and therefore formulated a way of visualising wave propagation. This became known as 'Huygens' Principle'.

• Huygens theory was the successful theory of light wave motion in three dimensions. Huygen, suggested that light wave peaks form surfaces like the layers of an onion. In a vacuum, or other uniform mediums, the light waves are spherical, and these wave surfaces advance or spread out as they travel at the speed of light.

7. The Combination of solenoid and toroid is used in which apparatus (appliance) to produce high magnetic field? [RRB RPF/RPSF SI Exam, 11.01.2019 Shift-II]

(1) Generator
(2) Synchotron
(3) Rectifier
(4) Dipole

Correct Answer: (2) Synchotron

Solution:Synchrotron, cyclic particle accelerator in which a charged particle is accelerated to very high energies in the presence of an alternating electric field while confined to a constant circular orbit by a magnetic field. The magnetic field serves to bend or deflect the path of the charged particles. The solenoid and the toroid are two pieces of equipment which generate magnetic fields. The solenoid is a coil of wire that acts like an electromagnet when a flow of electricity passes through it. A toroid is a coil of insulated or enameled wire wound on a donut-shaped form made of powdered iron.

8. Big Bang theory was given by- [RRB RPF/RPSF SI Exam, 11.01.2019 Shift-II]

(1) Thomas Gold
(2) George Lamaitre
(3) Harry Hess
(4) Alfred Vegenar

Correct Answer: (2) George Lamaitre

Solution:According to the Big Bang theory, the expansion of the observable universe began with the explosion of a single particle at a definite point in time. This startling idea first appeared in scientific form in 1931, in a paper by Georges Lemaître, Belgian a cosmologist and Catholic priest. The theory, accepted by nearly all astronomers today. was a radical departure from scientific orthodoxy in the 1930s.

9. What is the SI unit of (electric) current density? [RRB RPF/RPSF SI Exam, 11.01.2019 Shift-II]

(1) mA²
(2) Am²
(3) A/m²
(4) m/A²

Correct Answer: (3) A/m²

Solution:The amount of electric current traveling per unit cross-section area is called Current Density. In Si base. unite, the electric current density is measured in amperes per square metre or A/m²

10. The rate of the reaction in terms of the concentration of reactants is called: [RRB RPF/RPSF SI Exam, 11.01.2019 Shift-II]

(1) Current rate
(2) Rate related law
(3) Rate constant
(4) Molar law

Correct Answer: (2) Rate related law

Solution:The rate of a chemical reaction at a given temperature may depend on the concentration of one or more reactants and products. The representation of rate of reaction in terms of concentration of the reactants is known as rate law. It is also called as rate equation or rate expression.

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