Free & Premium Study Material · Online Courses · Instant Download+91 99398 78821 · support@downloadstore.in
downloadstoreSTUDY MATERIAL
LoginRegister🛒0

Modern Physics

97 MCQ questions with answers and explanations · page 3 of 4

Test yourself▶ 25 question test▶ 50 question test

Q51. What is the Coolidge tube used to produce?

  1. Aradio waves
  2. Bmicrowaves
  3. CX-rays
  4. Dgamma rays
Show answer & explanation

Answer: C) X-rays

Q52. Due to what is the huge amount of energy released in the explosion of an atomic bomb?

  1. Aconversion of matter into energy
  2. Bconversion of chemical energy into heat energy
  3. Cconversion of mechanical energy into nuclear energy
  4. Dconversion of neutrons into protons
Show answer & explanation

Answer: A) conversion of matter into energy

Q53. At what temperature can superconductivity be of great economic importance, leading to savings of millions of rupees?

  1. Aat extremely low temperatures
  2. BThe temperature at which it becomes a semiconductor
  3. Cat normal temperature
  4. Dat extremely high temperatures
Show answer & explanation

Answer: C) at normal temperature

Q54. X-rays are used to study crystal structure because-

  1. AThe crystal completely absorbs X-rays.
  2. BThe wavelength of X-rays and the interatomic distance of the crystal are of the same order of magnitude.
  3. CX-rays have very small wavelengths, comparable to the interatomic distances of a crystal.
  4. DThe crystal is completely transparent to X-rays.
Show answer & explanation

Answer: B) The wavelength of X-rays and the interatomic distance of the crystal are of the same order of magnitude.

Q55. Which of the following metals is used as a semiconductor in transistors?

  1. ACopper
  2. BGermanium
  3. Cgraphite
  4. DSilver
Show answer & explanation

Answer: B) Germanium

Q56. Photoelectric effect is explained as the ejection of electrons from the metal surface under which condition?

  1. Amay it get warm
  2. BIt is placed in a strong electric field
  3. CElectrons of suitable velocity collide with it.
  4. Dlight of appropriate wavelength falls on it
Show answer & explanation

Answer: D) light of appropriate wavelength falls on it

Q57. When two p and p type semiconductors are brought into contact, the pn junction they form acts as?

  1. Aamplifier
  2. BDriver
  3. Coscillator
  4. Drectifier
Show answer & explanation

Answer: D) rectifier

Q58. Why are appropriate impurities added to a semiconductor depending on its use?

  1. Aincrease its electrical conductivity
  2. Bincrease its electrical resistivity
  3. Cenhance its working method
  4. Dto make it capable of withstanding higher voltages
Show answer & explanation

Answer: A) increase its electrical conductivity

Q59. NPN transistors are superior to PNP transistors because-

  1. Aare cheap
  2. BThere is less energy loss in these.
  3. CThere is a greater flow of electrons in them
  4. Dhave the ability to tolerate high temperatures
Show answer & explanation

Answer: C) There is a greater flow of electrons in them

Q60. Diode is a device which allows current to

  1. Aallows flow in one direction
  2. BAllows flow in both directions
  3. CDoes not allow flow in any direction
  4. Dnone of the above
Show answer & explanation

Answer: A) allows flow in one direction

Q61. Which type of electromagnetic radiation is used for remote control of television?

  1. AInfrared
  2. BUltraviolet
  3. CScene
  4. Dnone of the above
Show answer & explanation

Answer: A) Infrared

Q62. Television signals cannot be received beyond a certain distance because-

  1. AThe signs are weak
  2. BThe antenna is weak
  3. Cabsorbs air signals
  4. Dthe surface of the earth is curved
Show answer & explanation

Answer: D) the surface of the earth is curved

Q63. When arsenic atoms are added to the germanium lattice, what does it become?

  1. Aexternal semiconductor
  2. Binsulating
  3. CSuper Conductor
  4. DDifferential Semi-conductor
Show answer & explanation

Answer: A) external semiconductor

Q64. What is radar used for?

  1. Adetection of submerged submarines
  2. BReceiving signals from a radio receiver
  3. CIdentifying distant objects and detecting energy
  4. Dlocating the satellite
Show answer & explanation

Answer: C) Identifying distant objects and detecting energy

Q65. Who takes three-dimensional pictures?

  1. AHolography
  2. BPhotography
  3. CPhotochromatic
  4. DRadiography
Show answer & explanation

Answer: A) Holography

Q66. Laser beam is used for-

  1. ALaser beam is used
  2. Bin cardiac medicine
  3. Cin eye medicine
  4. DIn kidney therapy
Show answer & explanation

Answer: C) in eye medicine

Q67. The phenomenon associated with forming a three-dimensional image by the interference of two light rays emanating from a laser or any other coherent light source is called –

  1. Aoptical photography
  2. BX-ray photography
  3. CRadiation Illustration
  4. DHolography
Show answer & explanation

Answer: D) Holography

Q68. What is photoelectric effect?

  1. Ainstantaneous process
  2. Bdelayed process
  3. CEmission of protons
  4. DNeutron emission
Show answer & explanation

Answer: A) instantaneous process

Q69. Who treats stones without surgery?

  1. AX-ray
  2. Bpleuroscopy
  3. CLaser
  4. Dultrasound
Show answer & explanation

Answer: C) Laser

Q70. Which one of the following is not a property of X-rays?

  1. AThey are deflected by electric fields
  2. BThey are not deflected by magnetic fields.
  3. CTheir penetration length in matter is high.
  4. DIt has a much shorter wavelength than visible light.
Show answer & explanation

Answer: A) They are deflected by electric fields

Q71. What can X-rays be used for?

  1. ADetecting gold underground
  2. BDetecting heart disease
  3. CDetection of flaws in precious stones and diamonds
  4. Dcutting and welding metal
Show answer & explanation

Answer: C) Detection of flaws in precious stones and diamonds

Q72. TV remote control works on the principle of…

  1. Ainfrared
  2. BBluetooth technology
  3. Claser technology
  4. Dultrasonic wave
Show answer & explanation

Answer: A) infrared

Q73. How do stars get their energy?

  1. Aas a result of nuclear fusion
  2. Bfrom nuclear fission
  3. Cby chemical reaction
  4. Dby gravitational pull
Show answer & explanation

Answer: A) as a result of nuclear fusion

Q74. The recently discovered high temperature superconductor is-

  1. Apure rare earth metal
  2. BInorganic polymer
  3. CCeramic Oxide
  4. DMetal Alloys
Show answer & explanation

Answer: C) Ceramic Oxide

Q75. The semiconductor chip used in integrated circuits is made of-

  1. ABeryllium
  2. BCarbon
  3. CSilicon
  4. DZircon
Show answer & explanation

Answer: C) Silicon

1234
← Miscellaneous PhysicsSound →
💬