1. Which one of the following is the property of an ionic compound?
High melting and boiling points.
Explanation: Ionic compounds are very strong in nature. They require a lot of energy to break them. Therfore ionic compound have high melting and boiling points.
2. When do ionic compounds conduct electricity?
a) In the gaseous state
b) In the solid state
c) When dissolved in water
d) They never conduct
Answer: c
Explanation: Ionic compounds can conduct electricity only if their ions are free to move. Hence they behave as conductors when they are dissolved in the water.
3. Which of the following covalent compounds conduct electricity?
a) Silica
b) Graphite
c) Diamond
d) Hydrogen chloride
Answer: b
Explanation: Graphite is made up of carbon layer that can slide over the each other. Like metals, the electrons are free to move. Whereas, the rest of the compounds are made up of carbon atoms held together tightly. Therefore, graphite is the covalent compound that conducts the electricity.
4. Which of the following is a crystalline solid?
a) Anisotropic substances
b) Isotropic substances
c) Supercooled liquids
d) Amorphous solids
Answer: a.
Explanation: Crystalline solids are those in which atoms are arranged in an orderly fashion. They have directional properties and therefore that is called anisotropic substances.
5. Which of the following has body centered cubic structure?
a) Polonium
b) Copper
c) Nickel
d) Tungsten
Answer: d
Explanation: In tungsten, atoms are arranged in the all eight corners and has an additional atom in the centre satisfying the body centered cubic lattice condition.
6. Fluids cannot resist sheer stress.
a) True
b) False
Answer: a
Explanation: Fluids can't resist sheer stress because they do not deform. Rather they flow. Fluids are opaque to transverse waves therefore they have the inability to undergo sheering stress.
7. What is the effect of annealing on the elasticity of materials?
a) Increases the elasticity
b) Decreases the elasticity
c) Has no effect on elasticity
d) Distorts the material
Answer: b
Explanation: Annealing is the process of heating a material and then gradually cooling it. While annealing, constituent crystals are uniformly oriented and form larger crystal grains, which results in decrease in their elastic properties.
8. Which of the following is the characteristic of the black body?
a) A perfect absorber but an imperfect radiator
b) A perfect radiator but an imperfect absorber
c) A perfect radiator and a perfect absorber
d) A perfect conductor
Answer: c
9. The energy distribution is not uniform for any given
temperature in a perfect black body.
a) True
b) False
Answer: a
10. Mechanical waves are called elastic waves.
a) True
b) False
Answer: a
Explanation: Waves which require a medium for their propagation are called the mechanical waves. They are also called elastic waves because they depend on the elastic properties of a medium.
11. Which of the following waves can be transmitted through solids, liquids and gases?
a) Transverse waves
b) Electromagnetic waves
c) Mechanical waves
d) Longitudinal waves
Answer: d
12. Sound travels through a gas under which of the following condition?
a) Isothermal condition
b) Non-isothermal condition
c) Adiabatic condition
d) Transverse condition
Answer: c
13. In which medium sound travels faster?
a) Solid
b) Liquid
c) Gas
d) Water vapour
Answer: a
Explanation: Sound travels in solid with the highest speed because the coefficient of elasticity of solids is much greater than the coefficient of elasticity of liquids and gases.
14. How are sound waves with a frequency of 20Hz to 20,000Hz termed?
a) Inaudible sounds
b) Infrasonics
c) Ultrasonics
d) Audible sound
Answer: d
Explanation: Sound waves below the frequency of 20Hz are called infrasonics.
Sound waves above 20,000Hz is ultrasonics.
Both are inaudible.
Sound waves between 20Hz to 20,000Hz are the audible sounds.
15. What will be the velocity of sound in a perfectly rigid rod?
a) Infinity
b) Finite
c) Zero
d) Constant
Answer: a
Explanation: Velocity of sound in a perfectly rigid body will be infinite because the value of Young’s modulus of elasticity is infinite for a perfectly rigid rod.
16. The speed of sound in moist air is greater than that in the dry air.
a) True
b) False
Answer: a
Explanation: The density of water vapour is less than that of air. So the density of air mixed with water vapour is less than that of dry air. Hence the speed of sound in moist air is greater than that in dry air.
17. Which of the following effects can be used to produce ultrasonic waves?
a) Magnetostriction effect
b) Doppler Effect
c) Magnetic effect
d) Sound effect
Answer: a
18. What is cold welding?
a) Welding at very low temperature
b) Welding using ultrasonic waves
c) Welding under water
d) Welding at constant temperature
Answer: b
Explanation: Some materials cannot be welded at the high temperature. In such cases, the welding can be done at the room temperature using ultrasonics and is called cold welding.
19. What is the other name for ultrasonic flaw detector?
a) Destructive testing
b) Magnetostrictive testing
c) Non-destructive testing
d) Echo testing
Answer: c
20. Which of the following can be used in a vibrational analysis of structure?
a) Maser
b) Quarts
c) Electrical waves
d) Laser
Answer: d
21. What is the principle of fibre optical communication?
a) Frequency modulation
b) Population inversion
c) Total internal reflection
d) Doppler Effect
Answer: c
Explanation: In optical fibres, the light entering the fibre does not encounter any new surfaces, but repeatedly they hit the same surface. The reason for confining the light beam inside the fibres is the total internal reflection.
22. Which of the following is known as fibre optic back bone?
a) Telecommunication
b) Cable television
c) Delay lines
d) Bus topology
Answer: d
Explanation: Each computer on the network is connected to the rest of the computers by the optical wiring scheme called the bus topology, which is an application known as the fibre optic back bone.
23. What does the conductivity of metals depend upon?
a) The nature of the material
b) Number of free electrons
c) Resistance of the metal
d) Number of electrons
Answer: b
Explanation: The conducting property of a solid is not a function of a total number of electrons in the metal, but it is due to the number of valance electrons that is called free electrons.
24. What happens to the free electrons when an electric field is applied?
a) They move randomly and collide with each other
b) They move in the direction of the field
c) They remain stable
d) They move in the direction opposite to that of the field
Answer: d
25. Thermal conductivity is due to both photons and free electrons
a) True
b) False
View Answer
Answer: a
26. How is the resistance of semiconductor classified?
a) High resistance
b) Positive temperature co-efficient
c) Negative temperature co-efficient
d) Low resistance
Answer: c
27. What are the charge carriers in semiconductors?
a) Electrons and holes
b) Electrons
c) Holes
d) Charges
Answer: a
Explanation: In conductors, electrons are the charge carriers.
But into the semiconductors, both electrons and holes are charge carriers and will take part in the conduction.
28. Which of the following is a weak magnet?
a) Ferromagnetic material
b) Antiferromagnetic
c) Paramagnetic
d) Diamagnetic
Answer: d
Explanation: The diamagnets are called weak magnets because there is no permanent dipole moment. Remember Their net magnetic moment is zero.
29. In which of the following magnetic moment is zero?
a) Dia-magnetic material
b) Parra-magnetic material
c) Ferromagnetic material
d) Ferrimagnetic material
Answer: a
30. When does a diamagnetic material become normal material?
a) At critical temperature
b) Above critical temperature
c) Never
d) Below critical temperature
Answer: d
Explanation: Critical temperature is the temperature at which properties like magnetism changes.
31. When does a paramagnetic material become diamagnetic material?
a) At critical temperature
b) Above critical temperature
c) Below critical temperature
d) Never
Answer: c
32. Which of the following is a strong magnet?
a) Diamagnetic material
b) Paramagnetic material
c) Antiferromagnetic material
d) Ferromagnetic material
Answer: d
Explanation: The ferromagnetic materials have a permanent dipole moment. So they act as the strong magnets.
33. What is the material used in two port device?
a) Ferromagnets
b) Ferrites
c) Antiferromagnets
d) Paramagnets
Answer: b
Explanation: The ferrites have low hysteresis loss and eddy current loss. Hence they are used in two port devices such as gyrator, circulator and isolator.
34. When does a normal conductor become a superconductor?
a) At normal temperature
b) At Curie temperature
c) At critical temperature
d) Never
Answer: c
Explanation: The temperature at which a normal conductor loses its resistivity and becomes a superconductor is known as transition temperature or the critical temperature.
35. Superconductors can be used as a memory or storage elements in computers.
a) True
b) False
Answer: a
Explanation: Since the current in superconducting ring can flow without any change in its value, it can be used as a memory or storage element in computers.
36. Which of the following restricts the flow of electrical energy?
a) Superconductors
b) Passive dielectrics
c) Polar molecules
d) Active dielectric
Answer: b
High melting and boiling points.
Explanation: Ionic compounds are very strong in nature. They require a lot of energy to break them. Therfore ionic compound have high melting and boiling points.
2. When do ionic compounds conduct electricity?
a) In the gaseous state
b) In the solid state
c) When dissolved in water
d) They never conduct
Answer: c
Explanation: Ionic compounds can conduct electricity only if their ions are free to move. Hence they behave as conductors when they are dissolved in the water.
3. Which of the following covalent compounds conduct electricity?
a) Silica
b) Graphite
c) Diamond
d) Hydrogen chloride
Answer: b
Explanation: Graphite is made up of carbon layer that can slide over the each other. Like metals, the electrons are free to move. Whereas, the rest of the compounds are made up of carbon atoms held together tightly. Therefore, graphite is the covalent compound that conducts the electricity.
4. Which of the following is a crystalline solid?
a) Anisotropic substances
b) Isotropic substances
c) Supercooled liquids
d) Amorphous solids
Answer: a.
Explanation: Crystalline solids are those in which atoms are arranged in an orderly fashion. They have directional properties and therefore that is called anisotropic substances.
5. Which of the following has body centered cubic structure?
a) Polonium
b) Copper
c) Nickel
d) Tungsten
Answer: d
Explanation: In tungsten, atoms are arranged in the all eight corners and has an additional atom in the centre satisfying the body centered cubic lattice condition.
6. Fluids cannot resist sheer stress.
a) True
b) False
Answer: a
Explanation: Fluids can't resist sheer stress because they do not deform. Rather they flow. Fluids are opaque to transverse waves therefore they have the inability to undergo sheering stress.
7. What is the effect of annealing on the elasticity of materials?
a) Increases the elasticity
b) Decreases the elasticity
c) Has no effect on elasticity
d) Distorts the material
Answer: b
Explanation: Annealing is the process of heating a material and then gradually cooling it. While annealing, constituent crystals are uniformly oriented and form larger crystal grains, which results in decrease in their elastic properties.
8. Which of the following is the characteristic of the black body?
a) A perfect absorber but an imperfect radiator
b) A perfect radiator but an imperfect absorber
c) A perfect radiator and a perfect absorber
d) A perfect conductor
Answer: c
9. The energy distribution is not uniform for any given
temperature in a perfect black body.
a) True
b) False
Answer: a
10. Mechanical waves are called elastic waves.
a) True
b) False
Answer: a
Explanation: Waves which require a medium for their propagation are called the mechanical waves. They are also called elastic waves because they depend on the elastic properties of a medium.
11. Which of the following waves can be transmitted through solids, liquids and gases?
a) Transverse waves
b) Electromagnetic waves
c) Mechanical waves
d) Longitudinal waves
Answer: d
12. Sound travels through a gas under which of the following condition?
a) Isothermal condition
b) Non-isothermal condition
c) Adiabatic condition
d) Transverse condition
Answer: c
13. In which medium sound travels faster?
a) Solid
b) Liquid
c) Gas
d) Water vapour
Answer: a
Explanation: Sound travels in solid with the highest speed because the coefficient of elasticity of solids is much greater than the coefficient of elasticity of liquids and gases.
14. How are sound waves with a frequency of 20Hz to 20,000Hz termed?
a) Inaudible sounds
b) Infrasonics
c) Ultrasonics
d) Audible sound
Answer: d
Explanation: Sound waves below the frequency of 20Hz are called infrasonics.
Sound waves above 20,000Hz is ultrasonics.
Both are inaudible.
Sound waves between 20Hz to 20,000Hz are the audible sounds.
15. What will be the velocity of sound in a perfectly rigid rod?
a) Infinity
b) Finite
c) Zero
d) Constant
Answer: a
Explanation: Velocity of sound in a perfectly rigid body will be infinite because the value of Young’s modulus of elasticity is infinite for a perfectly rigid rod.
16. The speed of sound in moist air is greater than that in the dry air.
a) True
b) False
Answer: a
Explanation: The density of water vapour is less than that of air. So the density of air mixed with water vapour is less than that of dry air. Hence the speed of sound in moist air is greater than that in dry air.
17. Which of the following effects can be used to produce ultrasonic waves?
a) Magnetostriction effect
b) Doppler Effect
c) Magnetic effect
d) Sound effect
Answer: a
18. What is cold welding?
a) Welding at very low temperature
b) Welding using ultrasonic waves
c) Welding under water
d) Welding at constant temperature
Answer: b
Explanation: Some materials cannot be welded at the high temperature. In such cases, the welding can be done at the room temperature using ultrasonics and is called cold welding.
19. What is the other name for ultrasonic flaw detector?
a) Destructive testing
b) Magnetostrictive testing
c) Non-destructive testing
d) Echo testing
Answer: c
20. Which of the following can be used in a vibrational analysis of structure?
a) Maser
b) Quarts
c) Electrical waves
d) Laser
Answer: d
21. What is the principle of fibre optical communication?
a) Frequency modulation
b) Population inversion
c) Total internal reflection
d) Doppler Effect
Answer: c
Explanation: In optical fibres, the light entering the fibre does not encounter any new surfaces, but repeatedly they hit the same surface. The reason for confining the light beam inside the fibres is the total internal reflection.
22. Which of the following is known as fibre optic back bone?
a) Telecommunication
b) Cable television
c) Delay lines
d) Bus topology
Answer: d
Explanation: Each computer on the network is connected to the rest of the computers by the optical wiring scheme called the bus topology, which is an application known as the fibre optic back bone.
23. What does the conductivity of metals depend upon?
a) The nature of the material
b) Number of free electrons
c) Resistance of the metal
d) Number of electrons
Answer: b
Explanation: The conducting property of a solid is not a function of a total number of electrons in the metal, but it is due to the number of valance electrons that is called free electrons.
24. What happens to the free electrons when an electric field is applied?
a) They move randomly and collide with each other
b) They move in the direction of the field
c) They remain stable
d) They move in the direction opposite to that of the field
Answer: d
25. Thermal conductivity is due to both photons and free electrons
a) True
b) False
View Answer
Answer: a
26. How is the resistance of semiconductor classified?
a) High resistance
b) Positive temperature co-efficient
c) Negative temperature co-efficient
d) Low resistance
Answer: c
27. What are the charge carriers in semiconductors?
a) Electrons and holes
b) Electrons
c) Holes
d) Charges
Answer: a
Explanation: In conductors, electrons are the charge carriers.
But into the semiconductors, both electrons and holes are charge carriers and will take part in the conduction.
28. Which of the following is a weak magnet?
a) Ferromagnetic material
b) Antiferromagnetic
c) Paramagnetic
d) Diamagnetic
Answer: d
Explanation: The diamagnets are called weak magnets because there is no permanent dipole moment. Remember Their net magnetic moment is zero.
29. In which of the following magnetic moment is zero?
a) Dia-magnetic material
b) Parra-magnetic material
c) Ferromagnetic material
d) Ferrimagnetic material
Answer: a
30. When does a diamagnetic material become normal material?
a) At critical temperature
b) Above critical temperature
c) Never
d) Below critical temperature
Answer: d
Explanation: Critical temperature is the temperature at which properties like magnetism changes.
31. When does a paramagnetic material become diamagnetic material?
a) At critical temperature
b) Above critical temperature
c) Below critical temperature
d) Never
Answer: c
32. Which of the following is a strong magnet?
a) Diamagnetic material
b) Paramagnetic material
c) Antiferromagnetic material
d) Ferromagnetic material
Answer: d
Explanation: The ferromagnetic materials have a permanent dipole moment. So they act as the strong magnets.
33. What is the material used in two port device?
a) Ferromagnets
b) Ferrites
c) Antiferromagnets
d) Paramagnets
Answer: b
Explanation: The ferrites have low hysteresis loss and eddy current loss. Hence they are used in two port devices such as gyrator, circulator and isolator.
34. When does a normal conductor become a superconductor?
a) At normal temperature
b) At Curie temperature
c) At critical temperature
d) Never
Answer: c
Explanation: The temperature at which a normal conductor loses its resistivity and becomes a superconductor is known as transition temperature or the critical temperature.
35. Superconductors can be used as a memory or storage elements in computers.
a) True
b) False
Answer: a
Explanation: Since the current in superconducting ring can flow without any change in its value, it can be used as a memory or storage element in computers.
36. Which of the following restricts the flow of electrical energy?
a) Superconductors
b) Passive dielectrics
c) Polar molecules
d) Active dielectric
Answer: b
