The blue colour of the sky is due to___________________?

A. Diffraction
B. Reflection
C. Polarization
D. Scattering

When one mirror of a Michelson Interferometer is moved a distance of 0.5 mm we observe 2000 fringes. What will be wavelength of light used ?

A. 5000 nm
B. 5000a
C. 500m
D. 2000um

Wavelength of X-rays falling at glancing angle of 30? on a crystal with atmic spacing 2 x 10-10 for the fist order diffraction is________________?

A. 4 x 10-10 m
B. 2 x 10-10 m
C. 0.02×10-10m
D. 20×10-10m

Electrical energy is measured in___________________?

A. Watt
B. Horse power
C. Kilo watt
D. Kilowatt hour

Electrical energy is converted to heat at the rate of___________________?

A. Irt
B. I2r
C. I2rt
D. Vit

A fuse is placed in series with the circuit to protect against__________________?

A. High power
B. High voltage
C. High current
D. Over heating

Which one of the following bulbs has the least resistance ?

A. 100 watt
B. 200 watt
C. 300 watt
D. 60 watt

Optical active crystals rotates the __________________?

A. Vibrating plane
B. Polarization plane
C. Diffraction plane
D. Interference plane

In double slit experiment we observe _____________________?

A. Interference fringes only
B. Diffraction fringes only
C. Both interference and diffraction fringes
D. Polirized frringes

Which one of the following properties of light does not change with the nature of the medium ?

A. Velocity
B. Wavelength
C. Amplitude
D. Frequency