Physics Questions Answers

• 22. Marie and Pierre Curie invented

  1. Radio
  2. Radium
  3. Radar
  4. Refrigerator

  Answer :

  Option B

  Explanation:

  Marie and Pierre Curie of France invented Radium in 1898,
  
  Radio was invented by G. Marconi of England in 1901,
  
  Radar was invented by Dr. A.H. Taylor and L.C. Young of USA in 1922,
  
  Refrigerator was invented by J. Harrison and A. Catlin of Britain in 1834.

• 23. What are audible sound waves ?

  1. Having frequency less than 20 Hz
  2. Having frequency between 20 Hz to 20000 Hz
  3. Having frequency more than 20000 Hz
  4. None of above

  Answer :

  Option B

• 24. Nuclear sizes are expressed in a unit named

  1. Fermi
  2. Angstrom
  3. Newton
  4. Tesla

  Answer :

  Option A

• 25. Radian is used to measure

  1. Temperature
  2. Intensity of Flame
  3. Angle
  4. Solid Angle

  Answer :

  Option C

  Explanation:

  Kelvin is used to measure Temperature,
  
  Candela is used to measure Intensity of flame,
  
  Steredian is used to measure Solid Angle.

• 26. Which instrument is used to measure the scattering of light by particles suspended in a liquid ?

  1. Nephetometer
  2. Ohmmeter
  3. Ondometer
  4. Pyrometer

  Answer :

  Option A

  Explanation:

  Ohmmeter - is used to measure electrical resistance in ohms,
  
  Ondometer - is used to measure frequency of electromagnetic waves,
  
  Pyrometer - is used to measure very high temperature.

• 27. What is refractive index ?

  1. it is defined as the ratio of speed of light in the medium to the speed of light in vacuum.
  2. it is defined as the ratio of speed of light in vacuum to the speed of light in the medium .
  3. it is defined as the product of speed of light in medium and in vacuum.
  4. None of above

  Answer :

  Option B

• 28. newton is used to measure

  1. Speed
  2. Volume
  3. Force
  4. Area

  Answer :

  Option C