Optical fibre works on the principle of total internal reflection. Each fibre consists of core and cladding. Refractive index of core is greater than cladding.

Correct Option: A

Optical fibre works on the principle of total internal reflection. Each fibre consists of core and cladding. Refractive index of core is greater than cladding.

Because the light from this is monochromatic i.e., single color light and will not split through water droplets.

Correct Option: B

Because the light from this is monochromatic i.e., single color light and will not split through water droplets.

There is always an inverted image of the object on the retina.

Correct Option: B

There is always an inverted image of the object on the retina.

The mirror used by a dentist to examine the teeth of patients is concave as concave mirror gives magnified image of the object.

Correct Option: A

The mirror used by a dentist to examine the teeth of patients is concave as concave mirror gives magnified image of the object.

The color of the star is an indication of its temperature according to Wein's displacement law
λ x T = b
where λ = Wavelength
T = Temperature and
b = Constant whose value is
2892 x 10^-6 mk

Correct Option: B

The color of the star is an indication of its temperature according to Wein's displacement law
λ x T = b
where λ = Wavelength
T = Temperature and
b = Constant whose value is
2892 x 10^-6 mk