05-01-2018, 04:33 PM
Doppler Effect
*Apparent change in frequency of a light or a sound wave when the source or the observer moves with respect to one another is called
Ans : Doppler Effect
*Red shift and blue shift occur due to - Doppler effect of light.
*Increase in frequency (decrease in wave length) of the visible light when it moves towards the observer is called
Ans : Blue shift
*Decrease in frquency (increase in wave length) of the visible light when it moves away from the observer is called
Ans : Red shift
*High pitch of the siren of an approaching ambulance which passes an observer is due to
Ans : Doppler effect
*Law associated with polarisation of light
Ans : Brewster's Law
Tyndal effect
*Scattering of light by the particles in a colloid is known as
Ans : Tyndal effect (Tyndal Scattering)
*Sunlight passing through a mist is an example of Tyndal effect.
*A blue colour is sometimes seen In the smoke emitted by motor cycles is due to
Ans : Tyndal effect
Lens
*A lens is a transparent medium bounded by two surfaces atleast one of which is a curved surface.
*Convex lens (Converging lens) is thicker at the centre and narrower at the edges.
*It is used in optical instruments, such as microscope, telescope etc for magnifying images.
*The lens in human eye
Ans : convex lens.
*Image formed in convex lens
Ans : Real and inverted
*Concave lens (diverging lens) is narrower at the centre and thicker at the edges.
*Image formed in concave lens
Ans : Virtual and erect
* Type of image formed by diverging lens -small, virtual image
*Lens is not used in pinhole camera.
*The ability of an optical instrument to produce separate images of two objects clearly is called
Ans : Resolving Power
*Focal length and power of a concave lens is always negative.
