Question

hiii !!!
plss answer..​

Answer 1

object distance = u (say)

image distance = v (let)

as, magnification produced = +4

therefore

$- \frac{ v}{( u)} = 4 \\ v = - 4u \\ using \: mirror \: formula \\ \frac{1}{v} + \frac{1}{( u)} = \frac{1}{ - 20} \\ \frac{1}{ - 4u} + \frac{1}{u} = - \frac{1}{20} \\ \frac{3}{4u} = - \frac{1}{20} \\ u = - 15cm$

so, object should be placed at a distance of 15cm to the left of the concave mirror

Answer 2

Here is ur answer attached given below--