Assertion: Minimum distance between object and its real image by a convex lens is $4 f$ .
Reason: If object distance from a convex lens is $2 f$ , then its image distance is also $2 f$ .

see full answer

21% of IItians & 23% of AIIMS delhi doctors are from Sri Chaitanya institute !!

An Intiative by Sri Chaitanya

If Assertion is false but the Reason is true.

If both Assertion and Reason are true and the Reason is not the correct explanation of the Assertion.

If Assertion is true, but the Reason is false.

If both Assertion and Reason are true and the Reason is correct explanation of the Assertion.

answer is A, B.

(Unlock A.I Detailed Solution for FREE)

Ready to Test Your Skills?

Check your Performance Today with our Free Mock Test used by Toppers!

Take Free Test

Detailed Solution

If D be the distance between the object and the real image , then v = D - u

Therefore , $\frac{1}{(D - u)} - \frac{1}{(- u)} = \frac{1}{+ f} \Rightarrow u^{2} - D u + D f = 0$

For all real values of u , ${(- D)}^{2} - 4 D f \geq 0 \Rightarrow D_{m i n} = 4 f$ ( Here object distance u must be greater than f )

Watch 3-min video & get full concept clarity