Q.31)-Who is the inventor of RADAR?
  • H.N. Van Tessel
  • William K. Rontgen
  • P.T. Farnswarth
  • A.H. Taylor and Lio C. Young
Q.32)-Who discovered X-Rays?
  • Roentgen
  • Becquerel
  • Marie curie
  • Wan Loo
Q.33)-X-Rays can be used.
  • To detect defects in precious stones and diamonds
  • To detect heart diseases
  • To detect gold under the earth
  • For cutting and welding of metals
Q.34)-Wavelength of visible spectrum is_______
  • 1300 A - 3000 A
  • 3900 A - 7600 A
  • 7800 A- 8000 A
  • 8500 A - 9800 A
Q.35)-In a Filament type Light bulb most of the electric power consumed appear as___________
  • Visible Light
  • Infrared Light
  • Ultraviolet
  • Fluorescent Light
Q.36)-Which of the following is used in MRI machine?
  • Sound wave
  • X-Rays
  • Ultrasonic wave
  • Magnetic wave
Q.37)-A wavelength of 0.3 m is produced in air and it travels at a speed of 300 m/s. Then it will be an-
  • Audible wave
  • Ultrasonic
  • Microwave
  • Infrasonic
Q.38)-Bolometer is used to measure which of the following?
  • Frequency
  • Temperature
  • Velocity
  • Wavelength
Q.39)-Coolidge tube is used to produce
  • Radio waves
  • Micro waves
  • X-Rays
  • Gamma Rays
Q.40)-Which of the following parts of the sunlight makes the solar cooker hot?
  • Ultraviolet
  • Red Light
  • Infrared
  • Cosmic rays