Write any one use for the concave mirrors.

A concave mirror is used as a base in the microscope as a condenser. This helps the mirror to concentrate the light passed through it to make sure the surroundings of the object are dark. By this method, we can view the object/specimen clearly. Also, only concave mirrors are used by dentists.

Write any one use for the convex mirrors.

A convex mirror is a spherical reflecting surface in which its bulging side faces the light source. There are numerous uses of convex mirror which is also referred to as a fish-eye mirror by automobile enthusiasts. Convex mirrors are widely used as rear ‐ view mirrors in automobiles and vehicles because it can diverge light beams and make virtual images.

Where will you keep an object in front of a concave mirror to get a real and diminished image?

When an object is kept beyond the centre of curvature of a concave mirror, a real and diminished image is formed. This image is an inverted image of the object. This type of image is always formed between the centre of curvature and the focus point of the concave mirror.

An object is placed in front of a concave mirror. It is observed that a virtual image is formed. Draw the ray diagram to show the image formation and hence derive the mirror equation 1 f = 1 u + 1 v .

Ray diagram to show the formation of a virtual image by concave mirror: Derivation of mirror equation using the above ray diagram: ∆ C A ' B ' and ∆ C A B are similar triangles. Hence, we can write: A ' B ' A B = C B ' C B = C P + P B ' C P - B P .......(i) D N is equal to A B and is a normal on the principal axis. ∆ F D N and ∆ F A ' B ' are similar triangles. The incident rays are considered to be paraxial rays hence, D and P are very close. We can write: A ' B ' A B = F B ' F D = F P + P B ' F D = F P + P B ' F P .....(ii) Using the above equations and substituting the values according to the sign convention we get: C P + P B ' C P - B P = F P + P B ' F P - 2 f + v - 2 f + u = - f + v - f ⇒ - 2 f 2 - f v = 2 f 2 - f u - 2 v f = u v ⇒ f u + f v = u v f On dividing both sides by u v f we get: 1 u + 1 v = 1 f The above equation is the required mirror equation.

E M B I B E

Physics Crash Course (Based on Revised Syllabus-2023)>Chapter 1 - Reflection of Light : Spherical Mirrors>Exercise>Q 6

EASY

12th ICSE

IMPORTANT

Earn 100

Define pole of a spherical mirror.

Important Questions on Reflection of Light : Spherical Mirrors

EASY

12th ICSE

IMPORTANT

Physics Crash Course (Based on Revised Syllabus-2023)>Chapter 1 - Reflection of Light : Spherical Mirrors>Exercise>Q 7

Describe the principle of focus of the mirror?

EASY

12th ICSE

IMPORTANT

Physics Crash Course (Based on Revised Syllabus-2023)>Chapter 1 - Reflection of Light : Spherical Mirrors>Exercise>Q 8

Define the centre of curvature of a spherical mirror?

EASY

12th ICSE

IMPORTANT

Physics Crash Course (Based on Revised Syllabus-2023)>Chapter 1 - Reflection of Light : Spherical Mirrors>Exercise>Q 9

What are paraxial rays?

MEDIUM

12th ICSE

IMPORTANT

Physics Crash Course (Based on Revised Syllabus-2023)>Chapter 1 - Reflection of Light : Spherical Mirrors>Exercise>Q 10

A point source $S$ is placed midway between two converging mirrors having equal focal lengths $f$ as shown in the figure. Find the values of $d$ for which only one image is formed.

Question Image

HARD

12th ICSE

IMPORTANT

Physics Crash Course (Based on Revised Syllabus-2023)>Chapter 1 - Reflection of Light : Spherical Mirrors>Exercise>Q 11

Prove that for a concave mirror, the radius of curvature is twice the focal length.

MEDIUM

12th ICSE

IMPORTANT

Physics Crash Course (Based on Revised Syllabus-2023)>Chapter 1 - Reflection of Light : Spherical Mirrors>Exercise>Q 12

Establish relation between focal length and radius of curvature for a spherical mirror.

MEDIUM

12th ICSE

IMPORTANT

Physics Crash Course (Based on Revised Syllabus-2023)>Chapter 1 - Reflection of Light : Spherical Mirrors>Exercise>Q 13

If the image formed by a spherical mirror for all positions of the object placed in front of it is always erect and diminished, what type of mirror is it? Draw a labelled ray diagram to support your answer.

EASY

12th ICSE

IMPORTANT

Physics Crash Course (Based on Revised Syllabus-2023)>Chapter 1 - Reflection of Light : Spherical Mirrors>Exercise>Q 14

What is the focal length of a plane mirror ?