The band of colours that we get when white light splits into its components is known as the
Refractive index
Spectrum
Prism
None of these
The geometric centre of a lens is called
Centre of curvature
Principal axis
Optical centre
Principal focus
A medium is said to be optically dense if the speed of light become
Faster
Slower
Not changed
Which of the following lens is thicker in the middle and thinner at the edges ?
Convex lens
Concave lens
The refractive index of a medium is expressed as the ratio of
The speed of light in air to the speed of light in the medium
The speed of light in medium to the speed of light in air
The speed of light in the medium to the speed of light in water
The speed of light in water to the speed of light in the medium
Which of the following help us to see tiny objects which are magnified many more times than a simple microscope ?
Compound microscope
Telescope
Stethoscope
When the object is beyond 2F, the image formed is
at F
at 2F
Between F and 2F
at infinity
Which of the following joins the centres of curvatures of the two spherical surface of the lens?
Radius of curvature
Name the scientist who is often considered as father of modern physics
Sir.Isaac Newton
Albert Einstein
Christian Huygens
Willebrord Snell
We use which of the following to see distant heavenly bodies clearly?
Simple microscope
