Q. Light Emitting Diodes (LED) is used in fancy electronic devices such as toys emit
? Visible light
Q. Optical fibre works on the
? Total internal reflection
Q. Light from the star, Alpha Centauri, which is nearest to the earth after the sun, reaches the earth in
? 4.2 years
Q. Supersonic plane fly with the speed
? Greater than the speed of sound
Q. Mach number is used in connection with the speed of
? Aircraft
Q. Stars which appear single to the naked eye but are double when seen through a telescope are
? Binaries
Q. ML2T-2 is the dimensional formula for
? Couple acting on a body
Q. One watt-hour is equivalent to
? 3.6 x 103 J
Q. Sir C.V. Raman was awarded Nobel Prize for his work connected with which of the following phenomenon of radiation?
? Scattering
Q. In which of the following industries is mica as a raw material?
? Electrical