Question

Assertion: Focal length of a convex mirror is $20\text{cm}$. If a real object is placed at a distance of $20\text{cm}$ from the mirror, its virtual, erect and diminished image will be formed.
Reason: If a virtual object is placed at $20\text{cm}$ distance behind the convex mirror, its image is formed at infinity.
Choose the correct option based on it.

• A. Assertion and reason both are correct and reason is the correct explanation of assertion
• B. Assertion and reason both are correct and reason is not the correct explanation of assertion
• C. Assertion is true, but reason is false
• D. Assertion is false, but reason is true.

Answer 1

The correct option is B Assertion and reason both are correct and reason is not the correct explanation of assertion

In a convex mirror, when a real object is placed at some distance from it then, by ray diagram, we know that its virtual, erect and diminished image is formed.
If a virtual object is placed at the focus of the convex mirror, then its real image will be formed at infinity because rays will seem to emerge from the focus.


Thus, assertion and reason both are correct and reason is not the correct explanation of assertion.