25 questions on “Physics GK Mock Test” objective questions series – electromagnetic wave, stationary waves, battery, chemical energy, sun planets, sun radiation, magnetometer, nuclear reactors coolant, comets, earth’s interior, centrifugal force, fluorescent lamp, sound, surface tension, radio waves, ultrasound etc.

This article is important for anyone who is preparing for civil services, Bank PO exam or other government exams as such questions have been asked in all these exams in general studies or general knowledge section.

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Question Section:

Que (26): Who firstly demonstrated experimentally the existence of electromagnetic wave?
A. Hertz
B. Amphere
C. Volt
D. Watt

Answer: A. Hertz,
Heinrich Hertz was a brilliant German physicist and experimentalist who demonstrated that the electromagnetic waves predicted by James Clerk Maxwell actually exist. 

Que (27): There is no net transfer of energy by the particles of the medium in which waves?
A. Longitudinal wave
B. Transverse Wave
C. Surface wave
D. Stationary wave

Answer: D. Stationary waves,
In a stationary wave, there is no transfer of energy.

Que (28): Conversion of chemical energy into electrical energy occurs in which thing?
A. Switch
B. Battery
C. Wire
D. Device

Answer: B. Battery,
A battery is a device that stores chemical energy and converts it to electrical energy. The chemical reactions in a battery involve the flow of electrons from one material (electrode) to another, through an external circuit.
There are many types of batteries viz. Lithium ion batteries, Carbon zinc batteries, Alkaline batteries etc.

Que (29): Where will be the Time period in a vibration magnetometer infinite?
A. North seeking pole
B. South seeking pole
C. At magnetic pole
D. At the center

Answer: C. At magnetic pole,
Time period in vibration magnetometer will be infinity at check-circle also known as the magnetic pole, as there is no horizontal geomagnetic field strength there.

Que (30): In order of their distances from the Sun, which planet lie between Mars and Uranus?
A. Neptune
B. Uranus
C. Mars
D. Jupiter and Saturn

Answer: D. Jupiter and Saturn,
The order of the planets in the solar system, starting nearest the sun and working outward is the following:
Mercury > Venus > Earth > Mars > Jupiter > Saturn > Uranus > Neptune > Pluto.

Que (31): Which is used as a coolant in nuclear reactors?
A. Helium
B. Heavy water
C. Liquid sodium
D. All of the above

Answer: D. All of the above,
Coolant is required to remove heat from the reactor.

Que (32): Comets revolve around which body?
A. Star
B. Planets
C. Sun
D. Randomly in space

Answer: C. Sun,
Comets revolve around the sun in elliptic orbit.

Que (33): Which layer of the earth is believed to have the heaviest mineral materials of highest density?
A. Northern
B. Southern
C. Central core
D. Inner core

Answer: D. Inner core,
The inner core is densest: not only is it made out of the densest components (iron & nickel plus small amounts of gold, platinum, tungsten, rhodium &c), but it is under the greatest compression owing to the overlying layers.

Que (34): The mapping of which part of earth is most difficult?
A. Interior of the Earth
B. Exterior of the earth
C. Mapping the rivers
D. Mapping the territories

Answer: A. Interior of the Earth.

Que (35): When milk is churned, how does the cream separate from it?
A. Due to gravitational force
B. Due to frictional force
C. Due to tension force
D. Due to the centrifugal force

Answer: D. Due to the centrifugal force,
Centrifugal force acts in an outward direction and due to this the heavier particles of milk experience more force and gets collected on the outer.

Que (36): Which gas is used in fluorescent lamp?
A. Sulphuric vapour
B. Neon Vapour
C. Nitrogen
D. Mercury Vapour

Answer: D. Mercury vapour.

Que (37): Sound travels faster in which thing?
A. Copper than in air
B. Gold than in air
C. Silver than in air
D. Iron than in air

Answer: D. Iron than in air,
The speed of sound depends on the medium in which it is transported. Sound travels fastest through solids, slower through liquids and slowest through gases.

Que (38): Liquid drop tend to assume spherical shape because of ________.
A. Gravity
B. Surface tension
C. Density
D. None of the above

Answer: B. Surface tension,
Surface tension is the tendency of liquid surfaces to shrink into the minimum surface area possible. Surface tension allows insects, usually denser than water, to float and slide on a water surface.

Que (39): What is an instrument for measuring the rate of transpiration by plants?
A. Accelerometer
B. Calorimeter
C. Anemometer
D. Potometer

Answer: D. Potometer.
A potometer is a device used for measuring the rate of water uptake of a leafy shoot which is almost equal to the water lost through transpiration.

Que (40): Which reflects back more sunlight as compared to other three?
A. Forest Land
B. Dessert Land
C. Land covered with fresh snow
D. Cemented road

Answer: C. Land covered with fresh snow,
Land covered with fresh snow reflects back more sunlight as compared to other three. Fresh snow and ice reflect 80 – 85% of the sunlight. Therefore, the skin of skiers is irradiated by sunlight from all sides, since the snow does not take up the light but reflects it and remains cold.

Que (41): Which substance does not have a melting point?
A. Diamond
B. Saphire
C. Hair
D. Air

Answer: D. Air.

Que (42): Sun radiates energy in which all radiation form?
A. Light
B. Ultraviolet
C. Infrared
D. All of the above

Answer: D. All of the above.

Que (43): By which a mixture of sand and naphthalene can be separated?
A. Evaporation
B. Precipitation
C. Sublimation
D. none of these

Answer: C. Sublimation,
A mixture of sand and naphthalene can be separated by “Sublimation”. Naphthalene sublimes easily as its molecules are held together by weak van der aal intermolecular forces.

Que (44): By which Radio waves of constant amplitude can be generated?
A. Ammeter
B. caloriemeter
C. Oscillator
D. none of these

Answer: C. Oscillator,
An oscillator is a circuit which produces a continuous, repeated, alternating waveform without any input. Oscillators basically convert unidirectional current flow from a DC source into an alternating waveform which is of the desired frequency, as decided by its circuit components

Que (45): Which is used to know the development of foetus in uterus?
A. X-ray
B. Uv Photoradiation
C. Ultrasound
D. MRI

Answer: C. Ultrasound,
Ultrasound is sound waves with frequencies higher than the upper audible limit of human hearing. It creates image of mother’s womb and is a safe way to check health of unborn baby.

Que (46): Which mirror is to be used to obtain a parallel beam of light from a small lamp ?
A. Convex Mirror
B. Concave Mirror
C. Optical Mirror
D. A mirror is not used at all

Answer: B. Concave mirror,
A concave mirror is often used behind the bulb in a lamp, searchlight or projector to give a parallel beam of light (the lamp is kept at the focus), but if the aperture of the mirror is too big the beam will spread out.

Que (47): Why are Metals good conductor of heat than insulator?
A. The absorb heat
B. They have a low melting point compared to toher
C. They contain free electrons
D. The electrons allow heat to pass

Answer: C. They contain free electrons,
Metals are good conductors of heat because of following two reasons :
a) Metal ions are closely packed in the metal lattice and thus the transfer of heat from one end to another is more efficient.
b) Availability of free electrons makes transfer of heat easier making it a good conductor of heat.

Que (48): If a material, placed in a magnetic field is thrown out of it, then the material behaves like:
A. Magnetic induction takes place
B. It becomes Diamagnetic
C. The material becomes zero in terms to magnetism
D. none of these

Answer: B. Diamagnetic,
Diamagnetism. A diamagnetic substance is one whose atoms have no permanent magnetic dipole moment. When an external magnetic field is applied to a diamagnetic substance such as bismuth or silver a weak magnetic dipole moment is induced in the direction opposite the applied field.

Que (49): If the temperature of a semiconductor rises it’s resistivity?
A. Increase
B. Decrease
C. Stays the same
D. all of these

Answer: Decreases.

Que (50): ‘mho’ is the unit of?
A. Electricity
B. Distance
C. Rainfall
D. Conductance

Answer: D. Conductance,
The mho is a unit of electrical conductance and is the reciprocal of the resistance in ohms, and is actually ohm spelled backwards. One mho is equal to one siemens, which is the SI derived unit of conductance.

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