# Physics MCQ (Multiple Choice Questions) - SchoolingAxis

Que- In an X-ray tube electrons each of charge e are accelerated through V potential difference allowed to hit a metal target. The wavelength of the X-rays emitted is

a. he/ev

b. he/Vc

c. eV/h

d. impossible to predict

Que- The minimum wavelength of X-rays can further be reduced by

a. Reducing the pressure or cooling the target.

b. Increasing the temperature of the filament.

c. Using a target element of higher atomic number.

d. Increasing the potential difference between the cathode and the target.

Answer- Increasing the potential difference between the cathode and the target.

Que- The characteristic X-rays spectrum is due to

a. The illumination of the target metal by ultra-violet radiation.

b. The bombardment of the target by protons.

c. The bombardment of target by electrons.

d. The absorption of ? radiation by the target metal.

Answer- The bombardment of target by electrons.

Que- The minimum wavelength of X-rays produced by the bombardment of electrons on the screen of a television set where the accelerating potential is 2.0K V will be

a. 6.2 x 10-10m

b. 9.1 x 10-18m

c. 3.11 x 10-10m

d. 4 x 10-10m

Que- Maximum frequency in the spectrum from X-ray tube is directly proportional to the

a. Number of incident electron i.e. filament current.

b. The kinetic energy of the incident electron i.e. the potential difference through which they are accelerated.

c. The soft target which can easily emit electrons.

d. all of above are correct.

Answer- The kinetic energy of the incident electron i.e. the potential difference through which they are accelerated.

Que- X-rays are diffracted by a crystal but not by a diffraction grating because

a. The ions in a crystal are well arranged.

b. The lines in a diffraction grating cannot reflect X-rays.

c. The penetration power of X-rays is high in a diffraction grating.

d. The wavelengths of X-rays are of the same order of magnitude as the separation between atoms in a crystal

Answer- The wavelengths of X-rays are of the same order of magnitude as the separation between atoms in a crystal

Que- UV radiation can be produced by

a. Heating the filament.

b. Electron excitation in the gas.

c. Ionization of atoms.

d. All the above.

Answer- Electron excitation in the gas.

Que- Wave-like characteristic of electron is demonstrated by

a. Line spectrum of atoms.

b. Production of x-rays.

c. Diffraction by crystalline solids.

d. Photoelectric effect.

Que- Electron cannot exist in the  nucleus it is confirmed by observing that

b. Its size as compare to proton and neutron is very small.

c. No antiparticle of electron is present.

d. The velocity of electron must be very high according to uncertainty principle.

Answer- The velocity of electron must be very high according to uncertainty principle.

Que- In normal state of energy the incident high energy photons will be

a. Stimulated.

b. Absorbed.

c. Cause X-ray emission.

d. Cause laser production.

Que- In laser production the state in which more atoms are in the upper state than in the lower one is called

a. Metal stable state.

b. Normal state.

c. Inverted population.

d. All the above.

Que- The metastable state for an atom in laser light is

a. 10-4 sec

b. 10-5 sec

c. 10-3 sec

d. 10-8 sec

Que- In He-Ne laser the lasing action is produced by

a. Ne only.

b. He-Ne both

c. Electrons of He.

d. Electrons Ne.

Que- Reflecting mirrors in laser is used to

a. Further stimulation

b. Lasing more

c. For producing more energetic lasers.

d. All

Que- The velocity of laser light is

a. Less than ordinary light.

b. More than ordinary light.

c. Equal to ordinary light.

d. Different for different colours or frequency.

Que- In nucleus of uranium the number of neutrons will be

a. 92

b. 235

c. 143

d. different for different isotopes

Que- During fusion of hydrogen into helium

a. energy is absorbed

b. energy is released

c. mass is increased due to energy absorption

d. mass is reduced due to energy released

Que- One amu is equal to

a. 1.66 x 10-27kg

b. 166 x 10-15ng

c. 166 x 10-20?g

d. all of above

Que- According to which one of following law the density of atom is uniform?

a. J.J.Thomson model

b. Rutherfords model

c. Bohrs model

d. all of above laws contradict the statement

Que- For chain reaction to build up the size of the radioactive target should be

a. greater than the critical size

b. less than the critical size

c. equal to the critical size

d. all of above can build up a change reaction

Answer- greater than the critical size

Que- Antimatter consists of

a. antiproton

b. antineutron

c. positron

d. all of above

Que- Neutron and proton are commonly known as

a. nucleon

b. meson

c. boson

d. quartz

Que- Half life of radium is 1590 years. In how many years shall the earth loss all its radium due to radioactive decay?

a. 1590x106 years

b. 1590x1012 years

c. 1590x1024 years

d. never

Que- Electrons

a. can exist inside the nucleus

b. cannot exist inside the nucleus

c. can exist both inside and outside the nucleus

d. do not know

Answer- cannot exist inside the nucleus

Que- Radioactivity is a ______ (A) Spontaneous activity  (B) Chemical property

a. A & B

b. B & C

c. C & A

d. A B & C

Que- Energy liberated when one atom of U-235 undergoes fission reaction is

a. 200MeV

b. 40MeV

c. 30MeV

d. 20MeV

Que- Transuranic elements have atomic number

a. greater than 72

b. greater than 82

c. greater than 92

d. greater than 102

Que- Nuclear forces exist between

a. proton-proton

b. proton-neutron

c. neutron-neutron

d. all of the above

Que- Mass defect per nucleon is

a. binding energy of nucleus

b. packing fraction

c. average energy of nucleus

d. all of above are one and same thing

Que- Tick the correct statement

a. moderators slow down the neutrons

b. moderators bring the neutrons to rest

c. moderators absorb the neutrons

d. moderators reflect the neutrons

Answer- moderators slow down the neutrons

Que- The bombardment of nitrogen with ?-particles will produce

a. neutron

b. Proton

c. electron

d. positron

Que- Diameter of an atom is approximately

a. 10-12m

b. 10-11m

c. 10-10m

d. 10-14m

Que- Average energy required to remove one nucleon from the nucleus is called

a. binding energy per nucleon

b. energy of decay

c. destruction energy

d. all of above

Que- Fission chain reaction in a nuclear reactor can be controlled by introducing

a. iron rods

b. graphite rods

d. platinum rods

Que- Charge on an electron was determine by

a. Ampere

b. Maxwell

c. Millikan

d. Thomson

Que- Charge on neutron is

a. plus 1.6 x 10-19C

b. zero

c. minus 1.6 x 10-19C

d. no definite charge

Que- A particle having the mass of an electron and the charge of a proton is called a

a. antiproton

b. positron

c. gamma rays

d. photon

Que- Mass of neutron is

a. 1.67 x 10-31 kg

b. 1.67 x 10-27 kg

c. 9.1 x 10-31 kg

d. 1.67 x 10-19 kg

Que- Nuclei having the same mass number but different atomic number are

a. Isotopes

b. Isobars

c. Isotones

d. Isomers

Que- A mass spectrograph (spectrometer) sorts out

a. molecules

b. ions

c. elements

d. isotopes

Que- Sum of the masses of constituent nucleons as compared to the mass of the resultant nucleus is

a. smaller

b. greater than 82

c. same

d. some times smaller some times greater

Que- The unit of radioactivity curie is equal to

a. 3.74 x 109 disintegration per sec

b. 3.70 x 1010 disintegration per sec

c. 3.55 x 1010 disintegration per sec

d. 3.60 x 1010 disintegration per sec

Answer- 3.70 x 1010 disintegration per sec

Que- During fission process a large amount of

a. heat energy is released

b. nuclear energy is released

c. chemical energy is released

d. light energy is released

Que- In liquid metal fast breeder reactor the type of uranium used is

a. 92U235

b. 92U238

c. 92U234

d. 92U239

Que- Radioactive materials can be identified by measuring their

a. hardness

b. density

c. mass

d. half life

Que- If one or more of the neutrons emitted during fission cab be used to build up further fission then the reaction is self sustained and is known as

a. fission reaction

b. fusion reaction

c. chain reaction

d. chemical reaction

Que- Pair production takes place in the vicinity of a heavy nucleus so that

a. net energy is conserved

b. net charge is conserved

c. net momentum is conserved

d. all of the above

Que- During an encounter with an atom ?-particle knocks out

a. protons

b. electrons

c. neutrons

d. nothing

Que- Various types of cancer are treated by

a. cobalt-60

b. strontium-90

c. carbon-14

d. nickel-63

Que- Geiger counter is suitable for

a. fast counting

b. extremely fast counting

c. slow counting

d. all situations

Que- Pair production cannot take place in vacuum as ________ is not conserved

a. energy

b. charge

c. mass

d. momentum

Que- CFC is used in

a. refrigeration

b. aerosol spray

c. plastic foam industry

d. all of above

Que- Average distance covered by ?-particle in air before its ionizing power ceases is called its

a. trajectory

b. range

c. firing level

d. limit

Que- The most useful tracer is

a. Sr-90

b. I-131

c. CA-41

d. C-14

Que- Pair production cannot take place in vacuum as

a. mass is not conserved

b. energy is not conserved

c. momentum is not conserved

d. charge is not conserved

Que- A device for producing high velocity nuclei is

a. cloud chamber

b. linear accelerator

c. a mass spectrograph

d. Wilson cloud chamber

Que- The maximum safe limit dose for persons working in nuclear power station are

a. 1 rem per week

b. 5 rem per week

c. 4 rem per week

d. 3 rem per week

Que- The centre of gravity of a sprinter during the race lies

b. Behind his feet

c. At the centre of the body

d. To the left side of the body

Que- Who enunciated the laws of planetary motion?

a. Nicolaus Copernicus

b. Johannes Kepler

c. Isaac Newton

d. Galileo

Que- The tidal waves on sea is mainly due to

a. Gravitational Effect of Moon on Earth

b. Gravitational Effect of Sun on Earth

c. Gravitational Effect of Earth on Moon

d. None of the above

Answer- Gravitational Effect of Moon on Earth

Que- The time period of a pendulum when taken to the Moon would:

a. Remain the same

b. Decrease

c. Become zero

d. Increase

Que- "God Particle" is

a. Neutrino

b. Higgs Boson

c. Meson

d. Positron

Que- In a refrigerator, the cooling system should always be

a. At the top

b. At the bottom

c. At the middle

d. 1.024x10^3

Que- In a refrigerator what produces the cooling ?

a. The ice which deposits on the freezer

b. The sudden expansion of a compressed gas

c. The evaporation of a volatile liquid

d. None of these

Que- Which of the following has the highest entropy?

a. Hydrogen

b. Diamond

c. Liquid nitrogen

d. Mercury

Que- Which of these branches of Physics deal with heat and temperature and their relation to energy and work?

a. Geophysics

b. Mechanics

c. Atomic Physics

d. Thermodynamics

Que- The characteristic invalid for heat radiation is that it travels :

a. In a straight line

b. In all directions

c. With the speed of light

d. Heating the medium through which it passes

Answer- With the speed of light

Que- The blue colour of water in the sea is due to

a. Absorption of other colours except blue by water molecules

b. Scattering of blue light by water molecules

c. Reflection of blue light by impurities in sea water

d. Reflection of blue sky by sea water

Answer- Absorption of other colours except blue by water molecules

Que- The bending of light when it passes around a corner or a slit is due to ________

a. Reflection

b. Refraction

c. Diffraction

d. Total internal reflection

Que- The colour of the ocean appears to be blue because the sunlight falling on it is

a. Reflected

b. Refracted

c. Diffracted

d. Scattered

Que- Which of the following statements is true when we see ''rainbow' ?

a. We face sun and raindrops

b. The Sun remains behind us and we face raindrops

c. In light rainfall, we face Sun

d. The sky remains clear and the sun is at lower position in the sky

Answer- The Sun remains behind us and we face raindrops

Que- Danger signals are generally red as red light

a. Is least bright

b. Undergoes least deviation

c. Has lowest velocity

d. Gives comfort to eye

Que- The bats can fly in the dark because

a. They can see the objects in darkness

b. They have weak legs and are likely to be attacked by predators

c. They generate flashes of light

d. They generate ultrasonic sound waves

Answer- They generate ultrasonic sound waves

Que- The device used for locating submerged objects under sea is.

a. Sonar

c. Laser

d. Maser

Que- The sounds having a frequency of 20 Hertz to 20,000 Hertz are known as

a. Audible sounds

b. Ultrasonics

c. Infrasonics

d. Megasonics

Que- In mirrors the back surface is coated with a thin layer of :

a. Mercury

b. Silver

c. Red oxide

d. Silver nitrate

Que- A light ray travelling from denser to rarer medium at an angle of incidence more than critical angle of concerned media pair suffers.

a. Reflection

b. Refraction

c. Diffraction

d. Total internal reflection

Que- When a body falls from an aeroplane, there is increase in its

a. Kinetic energy

b. Mass

c. Acceleration

d. Potential energy

Que- Which of the following never occurs singly in nature?

a. Inertia

b. Momentum

c. Force

d. Velocity

Que- The moment of inertia of a body does not depend upon

a. The mass of the body

b. The mass distribution in the body

c. The angular speed of the body

d. The axis of rotation of the body

Answer- The angular speed of the body

Que- Newton's first law of motion gives the concept of

a. Energy

b. Work

c. Momentum

d. Inertia

Que- For every action, there is an equal and opposite reaction, is Newton's

a. First law

b. Second law

c. Third law

d. Fourth law

Que- A small gap is left at the joints of rails in a railway track to

a. Avoid the tracks being distorted due to seasonal temperature variation

b. Avoid the heating of tracks to high temperature

c. Control the speed of train

d. Keep the rails equidistant

Answer- Avoid the tracks being distorted due to seasonal temperature variation

Que- Pipelines in cold countries often burst in winter, because

a. Water freezes and expands in its volume

b. Temperature of ice is less than that of water

c. Pipelines contract in their volume

d. Pipelines expand due to freezing

Answer- Water freezes and expands in its volume

Que- In severe winter, in cold countries water pipes burst because

a. Water expands on freezing

b. Contraction of water pipes

c. High atmospheric pressure

d. Combined effect of all the above three

Que- Railway tracks are banked on curves so that

a. Necessary centrifugal force may be obtained from the horizontal component of the weight of the train

b. No frictional force may be produced between the tracks and the wheels of the train

c. Necessary centripetal force may be obtained from the horizontal component of the weight of the train

d. The train may not fall down inwards

Answer- Necessary centripetal force may be obtained from the horizontal component of the weight of the train

Que- The density of the liquid when heated

a. Decreases

b. Increases

c. Does not change

d. May increase of decrease depending on pressure

Que- The modulus of elasticity for mild steel is approximately equal to

a. 210 kN/mm2

b. 100 kN/mm2

c. 80 kN/mm2

d. 10 kN/mm2

Que- The Hooke's law is valid for

a. Only proportional region of the stress strain curve

b. Entire stress strain curve

c. Entire elastic region of the stress strain curve

d. Elastic as well as plastic region of the stress strain curve

Answer- Only proportional region of the stress strain curve

Que- Gas thermometers are more sensitive than the liquid thermometers because the gases

a. Have large coefficient of expansion

b. Are lighter

c. Have low specific heat

d. Have high,specific heat

Answer- Have large coefficient of expansion

Que- What happens to a liquid, when the vapour pressure equals the atmospheric pressure?

a. The liquid cools

b. The liquid boils

c. No change

d. The liquid evaporates

Que- If the temperature of a place increases suddenly, the relative humidity

a. Increases

b. Decreases

c. Remains constant

d. Fluctuates

Que- In beta decay what is emitted?

a. Electron

b. Proton

c. Neutron

d. All of the above

Que- Which one of the following ray has minimum wavelength?

a. Gamma ray

b. Cosmic ray

c. Utraviolet ray

d. X-rays

Que- Nuclear Fission is caused by the impact of

a. Electron

b. Neutron

c. Proton

d. Deutron

Que- Radiocarbon dating technique is used to estimate the age of

a. Fossils

b. Rocks

c. Monuments

d. Soil

Que- Which of the following branch of Physics deal with study of Atomic Nuclei?

a. Nuclear Physics

b. Bio Physics

c. Atomic Physics

d. None of the above

Que- Gamma rays can cause

a. Gene mutation

b. Sneezing

c. Burning

d. Fever

Que- Green house effect is the heating up of the Earth's atmosphere which is due to

a. The ultraviolet rays

b. G-rays

c. The infra-red rays

d. X-rays

Que- Visible light has a higher frequency than