A. directly proportional to the wavelength and can be represented by a wave number
B. directly proportional to the velocity of the wave inversely proportional to the wavelength and can be represented by a wave number
C. directly proportional to the wavelength.

A. Doctor Elrchwig
B. Kissam
C. Zirm
D. All of the above

A. low exhaust velocity and. higher loss of mass during propulsion
B. high exhaust velocity and higher loss of mass during propulsion
C. high exhaust velocity and low loss of mass during propulsion
D. None of these

A. electric current
B. electrical resistance
C. magnetic field
D. electrical charge

A. For protection against the effect of external magnetic fields
B. For guarding the instruments against unauthorized handling
C. For protection against the effect of moisture in the air
D. For absorbing heat generated during the functioning of the instruments

A. Aluminium
B. Copper
C. Silicon
D. None of these

A. Collimator
B. Telescope
C. Refractive index
D. Spectrum

A. Gugeliemo Marconi
B. John Dalton
C. Albert Einstein
D. Louis Braille

A. Fahrenheit
B. Edison
C. Galileo
D. None

A. Sir Isaac Newton
B. Albert Einstein
C. Gugeliemo Marconi
D. Aryabhatta