Physics
The effective diameter of the circular outline of a spherical lens is known as
- focal length
- principal focus
- aperture of lens
- radius of curvature
Related Questions
The correct descending order of the electro magnetic waves according to their wavelengths is
- UV-rays, γ-rays, microwaves, infrared
- infrared, microwaves, UV-rays, γ-rays
- γ-rays, UV rays, Infrared rays, microwaves
- microwaves, infrared rays, UV rays, γ-rays
Absolute unit of work is
- joule
- erg
- Both (a) and (b)
- None of these
The frequency of a source is 20 kHz. The frequency of sound wave produced by it in water and air will be
- same as that source
- > 20 kHz
- < 20 kHz
- Depend upon velocity