Question

When an object is placed just outside the focal length of a concave mirror, the image is
O smaller than the object and virtual.
O larger than the object and virtual.
O smaller than the object and real.
O smaller than the object and reversed. larger than the object and real

Answer 1

Answer:

O larger than the object and real

Explanation:

As we know by the formula of mirror

$\frac{1}{d_i} + \frac{1}{d_o} = \frac{1}{f}$

here we know that

$d_o = (f_o + x)$

so we have

$\frac{1}{d_i} = \frac{1}{f_o} - \frac{1}{f_o + x}$

so we have

$d_i = \frac{(f_o)(f_o + x)}{x}$

so magnification is given as

$M = -\frac{d_i}{d_o}$

$M = - \frac{f_o}{x}$

so here we have

$|M| > 1$

so image will be larger than object and real