Question

a concave mirror of focal length 20cm is placed 50 cm from a wall. how far from tha wall an object is placed to form its real image on the wall?​

Answer 1

Answer:

given:-

f = -20 CM

u = -50 CM

to find = v

we know by using mirror formula

\frac{1}{v} + \frac{1}{u} = \frac{1}{f}

\frac{1}{v} - \frac{1}{50} = - \frac{1}{20}

\frac{1}{v} = - \frac{1}{20} + \frac{1}{50}

\frac{1}{v} = \frac{ - 5 + 2}{100}

\frac{1}{v} = \frac{ - 3}{100}

v = - \frac{100}{3}

v = 33.3 \: cm

Answer 2

given:-

f = -20 CM

u = -50 CM

to find = v

we know by using mirror formula

given:-

f = -20 CM

u = -50 CM

to find = v

we know by using mirror formula