Where will the image be formed when the object is at infinity ?
At F
At F on other side of the lens
At 2F
At 2F on other side of the lens
When we stand in sunlight we feel the heat due to the presence of
Infrared radiation
Ultraviolet radiation
Radio waves
Electromagnetic radiation
Rainbows are formed due to
Diffraction of light
Dispersion of light
Convergence of light
Divergence of light
Which of the following joins the centres of curvatures of the two spherical surface of the lens?
Centre of curvature
Radius of curvature
Principal axis
Optical centre
Law of photoelectric effect was discovered by
Sir Isaac Newton
Christian Huygens
Willebrord Snell
Albert Einstein
The distance between the optical centre and the principal focus of a lens is known as
Principal focus
Focal length
None of these
A medium is said to be optically dense if the speed of light become
Faster
Slower
Not changed
The ability of the eye lens to self adjust its focal length is termed as the
Power of accomodation
Persistance of vision
Reflection of light
Refractive index of kerosene is
1.33
1.49
1.44
2.42
The separation of a beam of white light into its constituent colours is known as
Refraction of light