12. Assertion: The focal length of a convex mirror is positive. Reason: Its centre of curvature lies to the right side of the pole of the mirror.12. Assertion: The focal length of a convex mirror is positive. Reason: Its centre of curvature lies to the right side of the pole of the mirror.
Answers
Answer:
both a and r is correct in both cases
Define the principal focus of a concave mirror.
Ans. It is a point on the principal axis where the rays of light parallel to principal axis meet.
Q2. The radius of curvature of a spherical mirror is 20 cm. What is its fucul length?
Q3. Name a mirror that can give an erect and enlarged image of an object.
Ans. Concave mirror.
Q4. Why do we prefer a convex mirror as a rear-view mirror in vehicles?
Ans. Convex mirror can cover a wider range and give erect and diminished image. Hence convex mirror is used as a rear-view mirror to get wider field of view.
Q5. Find the focal length of a convex mirror whose radius of curvature is 32 cm.
Ans. Radius of curvature R = 32 cm
Q6. A concave mirror produces three times magnified (enlarged) real image of un object placed at 10cm in front of it. Where is the image located?
Ans. Object distance u = �10 cm (concave minor)