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.

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 9

EASY

12th ICSE

IMPORTANT

Earn 100

What are paraxial rays?

Important Questions on Reflection of Light : Spherical Mirrors

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.

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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 ?

MEDIUM

12th ICSE

IMPORTANT

Physics Crash Course (Based on Revised Syllabus-2023)>Chapter 1 - Reflection of Light : Spherical Mirrors>Exercise>Q 15

An object AB is placed in front of a concave mirror as shown in the given diagram –

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$(i)$ Draw ray diagram to form image

$(ii)$ If half of the aperture of mirror is blackened, how the position and intensity of image is affected?

EASY

12th ICSE

IMPORTANT

Physics Crash Course (Based on Revised Syllabus-2023)>Chapter 1 - Reflection of Light : Spherical Mirrors>Exercise>Q 16

$A B$ is an incident beam of light and $C D$ is a reflected beam (the number of reflections for this may be $1$ or more than $1$ ) of light. $A B$ and $C D$ are separated by some distance (may be large). It is possible by placing what type of mirror on the right side?
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