Q- The mass density of a nucleus varies with the mass number A as
(a) A2 (b) A
(c) 1 A
(d) Å
Ans: (d)
Q- If a wire of resistivity is stretched to double its length, then its new resistivity will
(a) Be half
(b) Be double
(c) Be four times
(d) Not change
Ans: (d)
Q- g-rays are deflected by
(a) An electric field but not by a magnetic field
(b) A magnetic field but not by an electric field
(c) Both electric and magnetic field
(d) Neither electric field nor magnetic field
Ans: (d)
Q- The density of nuclear matter is of the order of
(a) 103 kg/m3
(b) 1010 kg/m3
(c) 1017 kg/m3
(d) 1024 kg/m3
Ans: (c)
Q- Which of the following statements are true?
I. All radioactive elements decay exponentially with time. II. Half-life time of radioactive element is the time required for one half of the radioactive atoms to disintegrate. III. Age of the earth can be determined by radioactive dating. IV. Half-life time of a radioactive element is fifty per cent of its average life period. Select the correct answer using the codes given below: Codes
(a) I and II (b) I, III and IV
(c) I, II and III (d) II and III
Ans: (c)
Q- The radioactive nuclide 228 88 Ra decays by the emission of three a-particles the nuclide X finally formed is
(a) 220 84 X (b) 222 86 X
(c) 216 82 X (d) 215 88 X
Ans: (c)
Q- In nuclear fission, the percentage of mass converted into energy is about
(a) 10% (b) 0.01%
(c) 0.1% (d) 1%
Ans: (c)
Q- Cathode rays can be deflected by
(a) Magnetic field
(b) Electric fields
(c) Both electric and magnetic fields
(d) None of the above
Ans: (c)
Q- Energy generation in stars is mainly due to
(a) Chemical reaction
(b) Fission of heavy nuclei
(c) Fusion of light nuclei
(d) Fusion of heavy nuclei
Ans: (c)
Q- A good moderator should
(a) Not be a gas only
(b) Not have appetite for neutrons only
(c) Be light in mass number only
(d) Be all above three
Ans: (d)
Q- The size of atomic nucleus is of the order of
(a) 10-15 m (b) 10-12 m
(c) 1014 m (d) 1010 m
Ans: (a)
Q- A radioactive element AZ X , on emitting an a-particle, changes into
(a) 2 A Z −Y (b) 4 2 A Z Y −−(c) A 4 Z Y −(d) None
Ans: (b)
Q- The ratio of atomic volume to nuclear volume is of the order of
(a) 1015 (b) 10-12
(c) 108 (d) 10-8
Ans: (a)
Q- The size of atom is of the order of
(a) 10-14 m (b) 10-12 m
(c) 10-10 m (d) 1010 m
Ans: (c)
Q- X210 has half-life of 5 days. The time taken for seven-eights of sample of X210 to decay is
(a) 15 days (b) 20 days
(c) 10 days (d) None of these
Ans: (a)
Q- Which of the following nuclei undergo fission when struck by thermal neutrons?
1. U235 2. U238
3. Pu239 Select the correct answer using the codes given below: Codes
(a) Only 1 and 2
(b) Only 2 and 3
(c) Only 1 and 3
(d) 1, 2 and 3
Ans: (c)
Q- The electrons are emitted in the photoelectric effect from a metal surface.
(a) Only if the frequency of the incident radiation is above a certain threshold value
(b) Only if the temperature of the surface is high
(c) At the rate of independent of the nature of the metal
(d) None of the above
Ans: (a)
Q- The number of atoms of a radioactive substance at t = 0 is 8 × 104. Its halflife period is 4 years. The number of atoms left undecayed will be 1 × 104 after an interval of
(a) 9 years (b) 12 years
(c) 16 years (d) None of these
Ans: (b)
Q- Nuclear forces are
(a) Attractive only
(b) Repulsive only
(c) Attractive or repulsive depending upon separation between nucleons
(d) Neither attractive nor repulsive
Ans: (c)
Q- Consider the following statements in a nuclear reactor, self sustained chain reaction is possible, because
1. More neutrons are related in each of the fission reaction.
2. The neutrons immediately take part in the fission process.
3. The fast neutrons are slowed down by graphite.
4. Every neutron released in the fission reaction initiates fission. Which of these statements are correct ?
(a) 1, 2 and 3 (b) 1 and 3
(c) 2 and 4 (d) 2 , 3 and 4
Ans: (a)
Q- (e/m) ratio of anode rays produced in discharge tube, depends on the
(a) Nature of the gas filled in the tube
(b) Nature of the material of anode
(c) Nature of the material of cathode
(d) All of the above
Ans: (a)
Q- Cathode rays are made up of electrons. Anode rays are made up of
(a) Protons only
(b) Protons and positrons only
(c) Positive residence of atom
(d) All positive particles of atom
Ans: (c)
Q- In any fission process. The ratio mass of fission products mass of parent nucleus is
(a) Greater than 1
(b) Equal to 1
(c) Less than 1
(d) Depends on the mass of the parent nucleus
Ans: (c)
Q- A strong argument for the particle nature of cathode rays is that they
(a) travel through vacuum
(b) produce florescence
(c) cast shadow
(d) get deflected in magnetic field
Ans: (c)
Q- When 30 15 P decays to become 30 14Si , the particle released is
(a) Electron (b) a-particle
(c) Neutron (d) Positron
Ans: (d)
Q- Thomson’s cathode ray tube experiment demonstrated that
(a) Cathode rays are streams of negatively charged ions.
(b) All the mass of an atom is essentially in the nucleus
(c) The e / m of electrons is much greater than the e / m of proton.
(d) The e / m ratio of the cathode ray particle changes when a different gas is placed in the discharge tube
Ans: (c)
Q- In the following nuclear reaction, 6 11 11C 5 B+ X What does X stand for?
(a) A proton (b) A neutron
(c) A neutrino (d) An electron
Ans: (c)
Q- In the following reaction 24 4 1 12Mg 2 He 14Si 0 x n , x is
(a) 28 (b) 27
(c) 26 (d) 22
Ans: (b)
Q- When a triton capture a proton, it becomes
(a) Neutron (b) Meson
(c) a-particle (d) Deuteron
Ans: (c)
Q- 228 12 Ra nucleus there are
(a) 140 protons and 88 neutrons
(b) 140 neutrons and 88 protons
(c) 226 protons and 88 neutrons
(d) 226 neutrons and 88 protons
Ans: (b)
Q- A nuclear reactor harnesses nuclear energy by
(a) Nuclear fusion
(b) Spontaneous fission
(c) Uncontrolled chain reaction
(d) Controlled chain reaction
Ans: (d)
Q- Consider the following metals:
1. Uranium
2. Radium
3. Plutonium Which of these are used in making nuclear weapons?
(a) 1 and 2 (b) 1, 2 and 3
(c) 2 and 3 (d) 1 and 3
Ans: (d)
Q- Percentage of the original number of atoms in a radioactive sample remaining at the end of one mean life is
(a) 50 (b) 60
(c) 63 (d) 37
Ans: (d)
Q- A b-particle is emitted by radioactive nucleus at the time of conversion of
(a) A nucleon into energy
(b) A positron into energy
(c) A neutron into a proton
(d) A proton into a neutron
Ans: (c)
Q- Match List-I (particle) with List-II (approximate rest energy in MeV) and select the correct answer using the codes given below the lists : List-I List-II
A. Electron 1. 940
B. Neutrino 2. 140
C. Neutron 3. 0.5
D. Pi-Meson 4. 0 Codes A B C D
(a) 2 4 1 3
(b) 3 4 1 2
(c) 3 1 4 2
(d) 2 1 4 3
Ans: (b)
Q- The number of electrons in an atom of atomic number Z and mass number A is
(a) Z (b) A
(c) A – Z (d) None of these
Ans: (a)
Q- Consider the following statements:
1. According to de Broglie hypothesis particle have wavelike characteristics.
2. When an electron and proton have the same de Broglie wavelength, they will have equal momentum. Which of the statements given above is/are correct?
(a) Only 1
(b) Only 2
(c) Both 1, 2
(d) Neither 1 nor 2
Ans: (c)
Q- If a U-238 nucleus splits into two identical parts, the two nuclei so produced will be
(a) Radioactive (b) Stable
(c) Isotopes (d) Isobars
Ans: (b)
Q- The half-life (T) and the disintegration constant (l) of the radioactive substance are related as
(a) lT = 1 (b) l T = 0.693
(c) 0.693 T (d) 0.693 T
Ans: (b)
Q- Which of the following has rest mass greater than others?
(a) Electron (b) Photon
(c) p–Meson (d) Positron
Ans: (c)
Q- In a discharge tube at 0.2 mm of Hg pressure, there is a formation of
(a) Crooke’s dark space with glow near the electrodes
(b) Crooke’s dark space
(c) Faraday’s dark space
(d) Both Crooke’s and Faraday’s space partially
Ans: (a)
Q- The half-life of a radioactive element which has only 1 32 of its original mass left after a lapse of 60 days is
(a) 12 days (b) 32 days
(c) 60 days (d) 64 days
Ans: (a)
Q- The fuel used in nuclear power plants is
(a) U-235 (b) U-238
(c) U-236 (d) U-239
Ans: (a)
Q- The mass of a neutron is nearly same as that of
(a) A proton (b) A meson
(c) An epsilon (d) An electron
Ans: (a)
Q- Fusion reaction takes place at high temperature because
(a) Atoms are ionized at high temperature
(b) Molecules break up at high temperature
(c) Nuclei break up at high temperature
(d) Kinetic energy is high enough to overcome repulsion at high temperature
Ans: (d)
Q- It is possible to understand nuclear fission on the basis of the
(a) Meson theory of the nuclear forces
(b) Proton-proton cycle
(c) Independent particle model of the nucleus
(d) Liquid drop model of nucleus
Ans: (d)
Q- Thermal neutrons can cause fission in
(a) 235U (b) 238U
(c) 238Pu (d) 232Th
Ans: (a)
Q- Energy equivalent to 0.001 mg is
(a) 9 × 107 erg (b) 9 × 107 J
(c) 9 × 1010 J (d) 3 × 107 erg
Ans: (b)
Q- An atom of mass number 15 and atomic number 7 captures an a-particle and then emits a proton. The mass number and atomic number of resulting atom will be respectively
(a) 14 and 2 (b) 15 and 3
(c) 16 and 4 (d) 18 and 8
Ans: (d)
Q- One-sixteenth of initial amount of a radioactive substance remains undecayed after two hours. The halflife of the substance is
(a) 15 min (b) 45 min
(c) 30 min (d) 60 min
Ans: (c)
Q- In b-decay
(a) A is unaffected, Z increases by 1
(b) A is unaffected, Z decreases by 1
(c) A increases by 1 and Z is unaffected
(d) none of the above
Ans: (a)
Q- In a-decay
(a) Mass number A decreases by 4 and atomic number Z increases by 2
(b) A decreases by 4 and Z decreases by 2
(c) A increases by 4 and Z increases by 2
(d) None of the above
Ans: (b)
Q- The equation given below shows the disintegration of the radioactive isotope of hydrogen 3 3 1T 2He X Which one of the following is X in the equation?
(a) Electron (b) Deutron
(c) Neutron (d) Positron
Ans: (a)
Q- If a proton of mass is moving with the velocity of light, its mass will be
(a) Unchanged (b) Large but finite
(c) Infinite (d) Zero
Ans: (c)
Q- Enriched uranium is better as a fuel for a nuclear reactor because it has greater proportion of
(a) 233U (b) 235U
(c) 238U (d) 239U
Ans: (b)
Q- If M is the atomic mass and A is its mass number, then M A A −is called
(a) Binding fraction
(b) Fermi energy
(c) Mass defect
(d) Packing fraction
Ans: (d)
Q- Consider the following statements:
1. Plutonium-239 can be made artificially.
2. Boron is used in a nuclear reactor to absorbs unwanted neutrons.
3. In nature, the availability of uranium-238 is much more than that of uranium-235. Which of these statement(s) is/are correct?
(a) Only 1 (b) 1 and 2
(c) 1, 2 and 3 (d) Only 3
Ans: (c)
Q- During a nuclear fusion reaction
(a) A heavy nucleus breaks into two fragments by itself
(b) A light nucleus bombarded by thermal neutrons breaks up
(c) A heavy nucleus bombarded by thermal neutrons breaks up
(d) Two light nuclei combine to give a heavier nucleus and possibly other products
Ans: (d)
Q- The half-life of radium is 6400 years. The fraction of a sample of radium that would remain undecayed after 6400 years is
(a) (b) 1 4
(c) 1 8
(d) 1 16
Ans: (d)
Q- A radioactive substance has a halflife of 4 months. Three fourths of the substance will decays in
(a) 6 months (b) 8 months
(c) 12 months (d) 16 months
Ans: (b)
Q- The nuclear 6C13 and 7N14 can be described as
(a) Isobars
(b) Isotone
(c) Isotopes of carbon
(d) None of the above
Ans: (b)
Q- One atomic mass unit is equal to
(a) Mass of one atom of hydrogen
(b) Mass of one atom of 6C12
(c) 1 12 th of the mass of one atom of 6C12
(d) None of the above
Ans: (c)
Q- The nucleus 115 48 Cd , after two successive b decays will give
(a) 115 50 Sn (b) 113 50 Sn
(c) 117 50 Sn (d) None
Ans: (a)
Q- The end product of the decay of 232 90 Th is 208 82 Pb . The number of alpha (a) and beta (b) particles emitted are respectively
(a) 3, 3 (b) 6, 4
(c) 6, 0 (d) 4, 6
Ans: (b)
Q- In the experiments for determination of e/m of electrons by Thomson method electric and magnetic fields are
(a) Parallel and both are perpendicular to the motion of the electron
(b) Both mutually parallel and also parallel to the motion of the electron
(c) Both mutually perpendicular and also perpendicular to the motion of the electron
(d) Both mutually perpendicular and have no relation with the motion of the electron
Ans: (c)
Q- The percentage of the original quantity of a radioactive material left after five half lives is approximately
(a) 1% (b) 3%
(c) 5% (d) 20%
Ans: (b)
Q- Which of the following particles is unstable?
(a) Proton (b) Electron
(c) Photon (d) Neutron
Ans: (d)
Q- The scientist who experimentally showed that electric charge is quantised only in terms of integral multiples of electronic charge is
(a) Max Born
(b) Max Planck
(c) Thomson
(d) Millikan
Ans: (d)
Q- Nucleon is a common name for
(a) Proton and electron
(b) Electron and neutron
(c) Neutron only
(d) Neutron and proton
Ans: (d)
Q- Fertile material among the following is
(a) U235 (b) Pu239
(c) U233 (d) U238
Ans: (d)
Q- The most penetrating radiation out of the following is
(a) X-rays (b) a-rays
(c) b-rays (d) g-rays
Ans: (d)
Q- What was the fissionable material used in the bomb dropped at Nagasaki (Japan) in the year 1945?
(a) Uranium
(b) Plutonium
(c) Neptunium
(d) None of the above
Ans: (b)
Q- Neutrino is a particle which
(a) Has no charge but has spin
(b) Is charged like electron and has spin
(c) Has no charge and no spin
(d) None of the above
Ans: (a)
Q- Energy transferred to a person through gamma rays is measured in units of
(a) Curies
(b) Rutherfords
(c) Roentgens
(d) None of the above
Ans: (c)
Q- In the photoelectric effect, electrons are emitted
(a) At a rate that is independent of the emitter
(b) At a rate that is proportional to the square of the amplitude of the incident radiation
(c) With a maximum velocity proportional to the frequency of incident radiation
(d) Only if the frequency of the incident radiation is above a threshold value
Ans: (d)
Q- To produce deflection in a television picture tube
(a) An electric field is used
(b) A magnetic field is used
(c) Both electric and magnetic fields are used
(d) None of the above
Ans: (b)
Q- The electron emitted in beta radiation originates from
(a) Inner orbits of atoms
(b) Free electrons existing in nucleus
(c) Decay of a neutron in a nucleus
(d) Photon escaping from the nucleus
Ans: (a)
Q- In gamma (g) decay
(a) Both A and Z increase by 1
(b) Both A and Z decrease by 1
(c) Neither A nor Z changes
(d) A is always equal to Z
Ans: (c)
Q- A photo sensitive material would emit electrons, if excited by photons beyond a threshold. To overcome the threshold, one would increase
(a) The voltage applied to the light source
(b) Intensity of light
(c) The wavelength of light
(d) The frequency of light
Ans: (d)
Q- Pick out the statement which is true
(a) The energy released per unit mass is more in fusion and that per atom is more in fission
(b) Both fission and fusion produce same amount of energy per atom as well as per unit mass
(c) The energy released per unit mass
(d) The energy released per atom is more in fusion then in fission
Ans: (a)
Q- Compton effect is associated with
(a) Positive rays(b) b-rays
(c) g-rays (d) X-rays
Ans: (d)
Q- The cathode ray particles originate in a discharge tube from the
(a) Cathode
(b) Anode
(c) Source of high voltage
(d) Residual gas
Ans: (a)
Q- Radioactivity was discovered by
(a) J.J. Thomson
(b) W. Roentgen
(c) H. Becquerel
(d) M. Curie
Ans: (c)
Q- The fusion of hydrogen into helium is more likely to take place
(a) At high temperature and high pressure
(b) At high temperature and low pressure
(c) At low pressure and low temperature
(d) None of the above
Ans: (a)
Q- Photoelectric effect can be explained by assuming that light
(a) Is a form of transverse wave
(b) Is a form of longitudinal wave
(c) Can be polarised
(d) Consists of quanta
Ans: (d)
Q- Photocells are used for the
(a) Reproduction of pictures from the cinema film
(b) Reproduction of sound from the cinema film
(c) Automatic switching of street light
(d) Both (b) and (c)
Ans: (d)
Q- Photoelectric effect supports quantum nature of light because
(a) There is a minimum frequency of light below which no photoelectrons are emitted
(b) The maximum KE of photoelectrons depends only on the frequency of light and hot on its intensity
(c) Even when the metal surface is faintly illuminated, the photoelectrons leave the surface immediately
(d) Electric charge of the photoelectrons is quantised
Ans: (a)
Q- Consider the following statements:
1. Atom bomb is based upon the principle of uncontrolled nuclear fusion.
2. Hydrogen bomb is based upon the principle of uncontrolled nuclear fission.
3. Nuclear reactor is based upon the principle of controlled nuclear fission. Which of the statements given above is/are correct?
(a) Only 3
(b) Only 1 and 2
(c) Only 2 and 3
(d) 1, 2 and 3
Ans: (a)
Q- If alpha, beta and gamma rays carry same momentum, which has the longest wavelength?
(a) Alpha rays
(b) Beta rays
(c) Gamma rays
(d) None, all have same wavelength
Ans: (d)
Q- Einstein’s mass-energy relation is given by the expression
(a) 1 2 2 E mv
(b) E mc2
(c) E = mgh
(d) None of the above
Ans: (b)
Q- The dual nature of light is exhibited by
(a) Diffraction and photoelectric effect
(b) Diffraction and reflection
(c) Refraction and interference
(d) Photoelectric effect
Ans: (a)
Q- Which of the following statement is correct?
(a) Two isobars always have the same mass number
(b) Two isotopes always have the same mass number
(c) Two isotones always have the same mass number
(d) Two isobars always have same atomic number
Ans: (a)
Q- Which of the following will deflect in electric field?
(a) g-rays (b) X-rays
(c) Cathode rays
(d) Ultraviolet rays
Ans: (c)
Q- The wavelength of the matter waves is independent of
(a) Charge (b) Momentum
(c) Velocity (d) Mass
Ans: (a)
Q- The nuclear force
(a) Obeys inverse square law of distance
(b) Obeys inverse third power law of distance
(c) Is a short range force
(d) Is equal in strength to the electromagnetic force
Ans: (c)
Q- Isotopes have the same
(a) Atomic number
(b) Mass number
(c) Avogadro’s number
(d) None of the above
Ans: (a)
Q- In nuclear reaction, there is conservation of
(a) Mass only
(b) Energy only
(c) Momentum only
(d) Mass-energy and momentum
Ans: (d)
Q- Beta rays emitted by radioactive substance are
(a) Electromagnetic radiations
(b) Charged particles emitted by the nucleus
(c) Electrons orbiting around the nucleus
(d) None of the above
Ans: (b)
Q- The main source of solar energy is
(a) Nuclear fission
(b) Nuclear fusion
(c) Combustion
(d) None of the above
Ans: (b)
Q- The mass defect per nucleon is called
(a) Binding energy
(b) Packing fraction
(c) Ionisation energy
(d) Excitation energy
Ans: (b)
Q- The important conclusion given by Millikan’s experiment about the charge is
(a) Charge is never quantised
(b) Charge has no definite value
(c) Charge is quantised
(d) Charge on oil drop always increases
Ans: (c)
Q- Neutron was discovered by
(a) J.J. Thomson
(b) James Chadwick
(c) Rutherford
(d) None of the above
Ans: (b)
Q- In photoelectric effect, the number of photo electrons emitted is proportional to
(a) Intensity of incident beam
(b) Frequency of incident beam
(c) Velocity of incident beam
(d) Work function of photo cathode
Ans: (a)
Q- Voltage applied between the electrodes of discharge tube is of the nature
(a) 220 V alternating voltage
(b) 220 V DC voltage
(c) Variable voltage
(d) Voltage obtained by induction coil
Ans: (d)
Q- Atomic power plant works on the principle of
(a) Fission
(b) Fusion
(c) Thermal combustion
(d) Combined effect of all the three
Ans: (a)
Q- Which is the incorrect statement of the following?
(a) Photon is a particle with zero rest mass
(b) Photon is a particle with zero momentum
(c) Photon travels with velocity of light in vacuum
(d) Photon even feel the pull of gravity
Ans: (b)
Q- Cathode rays are similar to visible light rays, in that
(a) They both can be deflected by electric and magnetic fields
(b) They both have a definite magnitude of wavelength
(c) They both can ionise the gas through which they pass
(d) They both can affect photographic plates
Ans: (d)
Q- Alpha rays emitted from a radioactive substance are
(a) Negatively charged particles
(b) Hydrogen nuclear
(c) Helium nuclear
(d) None of the above
Ans: (c)
Q- Hydrogen bomb is based upon the principle of
(a) Nuclear fission
(b) Nuclear fusion
(c) Controlled nuclear fission
(d) None of the above
Ans: (b)
Q- An atom bomb is based upon the principle of
(a) Nuclear fission
(b) Nuclear fusion
(c) Controlled chain reaction
(d) None of the above
Ans: (a)
Q- The fourth state of matter is known as
(a) Gas (b) Vapour
(c) Plasma (d) Electrons
Ans: (c)
Q- The mass-energy relation is the out come of
(a) Quantum theory
(b) General theory of relativity
(c) Field theory of relativity
(d) Special theory of relativity
Ans: (d)
Q- Curie is a unit of
(a) Energy of gamma rays
(b) Half-life
(c) Intensity of gamma rays
(d) Radioactivity
Ans: (d)
Q- Nuclear fission experiments show that the neutrons split the uranium nucleus into two fragments of about the same size. The process is accompanied by the emission of several
(a) Protons and positrons
(b) a-particles
(c) Neutrons
(d) Protons and a-particles
Ans: (c)
Q- Which of the particles has similar mass to that of the electron?
(a) Proton (b) Neutron
(c) Positron (d) Neutrino
Ans: (c)
Q- Particles which can be added to the nucleus of an atom without changing its chemical properties are
(a) Electrons (b) Protons
(c) Neutrons (d) a-particles
Ans: (c)
Q- The cause of fractional atomic weights of elements is the presence of
(a) Isobars
(b) Isotopes
(c) Isotones
(d) None of the above
Ans: (b)
Q- When the speed of electrons increases, then the value of the specific charge on an electron
(a) Increases
(b) Decreases
(c) Remains unchanged
(d) None of the above
Ans: (b)
Q- The colour of the +ve column in a gas discharge tube depends on
(a) The type of glass used to construct the tube
(b) The gas in the tube
(c) The applied voltage
(d) The material of the cathode
Ans: (b)
Q- Which of the following is not the property of cathode rays?
(a) It produces heating effect
(b) It does not deflect in electric field
(c) Its casts shadow
(d) It produces fluorescence
Ans: (b)
Q- When yellow light is incident on a surface no electrons are emitted while green light can emit. If red light is incident on the surface then
(a) No electrons are emitted
(b) Photons are emitted
(c) Electrons of higher energy are emitted
(d) Electrons of lower energy are emitted
Ans: (a)
Q- The maximum number of photo electrons released in photocell is independent of
(a) Nature of the cathode surface
(b) Frequency of incident ray
(c) Intensity of radiations incident on cathode surface
(d) None of the above
Ans: (b)
Q- Out of the following, the one which can pass through 20 cm thickness of steel is
(a) a-rays
(b) b-rays
(c) g-rays
(d) ultraviolet rays
Ans: (c)
Q- Gamma rays are
(a) Single ionised gas atom
(b) Helium nucleus
(c) Fast moving electron
(d) Electromagnetic waves
Ans: (d)
Q- An atomic pile is used for
(a) Producing X-rays
(b) Conducting nuclear fission
(c) Conducting thermonuclear fission
(d) Temperature
Ans: (b)
Q- Which one of the following is not a radioactive element?
(a) Uranium (b) Thorium
(c) Radium (d) Cadmium
Ans: (d)
Q- The mass number of a nucleus is
(a) Always less than its atomic number
(b) Always more than its atomic number
(c) Some times more than and some times equal to its atomic number
(d) None of the above
Ans: (c)
Q- The nucleus of an atom consists of
(a) Electrons and protons
(b) Neutrons only
(c) Neutrons and protons
(d) Protons, electrons and neutrons
Ans: (c)
Q- Nuclear forces are
(a) Spin dependent
(b) Charge dependent
(c) Long range
(d) None of the above
Ans: (a)
Q- Nuclear forces are mediated by
(a) Proton (b) Neutron
(c) Meson (d) Electron
Ans: (c)
Q- In which of the following decays, the atomic number decreases?
(a) b–decay (b) b+-decay
(c) a-decay (d) Both (b) and (c)
Ans: (d)
Q- The electron emitted in beta radiation originates from
(a) Inner orbit of atoms
(b) Free electrons existing in nucleus
(c) Decay of a neutron in a nucleus
(d) None of the above
Ans: (c)
Q- Direct conversion of solar energy with the use of photovoltaic cell results in the production of
(a) Optical energy
(b) Electrical energy
(c) Thermal energy
(d) Mechanical energy
Ans: (b)
Q- Superconductivity
(a) very feeble current
(b) very large current
(c) current without facing any resistance
(d) current due to positive particles
Ans: (c)
Q- Name the scientist who stated that matter can be converted into energy
(a) Boyle
(b) Lavoisier
(c) Avogadro
(d) Einstein
Ans: (d)