Question

Answer the following
a) Define a spherical mirror
b) Distinguish between a concave mirror and a convex mirror
c) What is the difference between a real image and a virtual image

Answer 1

Hint: In this question the parts are somewhat interlinked to each other. A spherical mirror is a portion of a spherical reflecting surface and since a spherical reflecting surface can have two shapes of its portion that is one bulging outwards and one bulging inwards so use this to approach the solution of this problem.

Complete step-by-step answer:
$\left( a \right)$ Spherical mirror
A spherical mirror is the mirror that has a shape of a piece cut out of the spherical surface.
There are two types of spherical mirror:
$\left( i \right)$ Concave mirror
$\left( {ii} \right)$ Convex mirror

$\left( b \right)$ Distinguish between the concave and the convex mirror

S/N	Differentiating property	Convex mirror	Concave mirror
1	Mirror shape	Convex mirror rounded or curved like the exterior of a circle or sphere.Also called a fish eye or diverging mirror.Convex mirror is curved outside.	Concave mirror is rounded or hollowed like the interior of a circle or a sphere.Also called a converging mirror.Concave mirror is curved inside.
2	Position of focus	Focus lies behind the mirror i.e. focal length is negative.	Focus lies in front of the mirror i.e. focal length is positive.
3	Position of center of curvature	Behind the mirror.	In front of the mirror.
4	Position of the object which is at infinity	At the focus and behind the mirror.	At the focus in front of the mirror.
5	Size of object when it is placed at infinity.	Highly diminished as compared to that of the object.	Much diminished as compared to that of the object.
6	Image of the object when it is placed at infinity.	Image is virtual and erect.	Image is real and inverted.

$\left( c \right)$ What is the difference between a real image and a virtual image?
$\left( i \right)$ A real image is always inverted in nature i.e. upside down whereas a virtual image is always erect in nature.
$\left( {ii} \right)$ A real image can be caught on the screen whereas a virtual image cannot be caught on the screen.
So this is the required answer.

Note – A real image will always be formed by a converging set of rays whereas a virtual image will be formed by a diverging set of rays. Since a convex mirror is always known as a diverging mirror therefore the image formed by it is always virtual however a concave mirror is simply a converging mirror therefore the images formed by it are real.