An object is moving towards a convex mirror with a constant velocity. P is the pole of mirror.

Options

A. magnification of the image increases with time.
B. magnificatin of the image decreases with time
C. velocity of the image increases with time
D. velocity of the image decreases with time

Answer

a.,c.

Explanation

`(1)/(y)+(1)/(-x)=(1)/(f)rArr(1)/(y)=(1)/(x)+(1)/(f)rArr y=(xf)/(x+f)`
`rArr (y)/(x)=(f)/(x+f)rArr ` as x decreases, so magnification increases.
Now, `(dy)/(dt)=((y)/(x))^(2)(dx)/(dt)rArrv=-((y)/(x))^(2)u`
As `(y)/(x)` increase, so v increases.