Question

The images of two persons A and B standing $1m$ apart in front of a plane mirror are A' & B' respectively. Image A' is at a distance of $2m$ from the mirror. Select the statements which are true.

• A. Distance between A & B' is equal to distance between A' & B
• B. Distance between A & B is less than distance between A' & B
• C. Distance between B & B' is equal to distance between A & A'
• D. Distance between B & mirror is equal to distance between A & B

Answer 1

Answer: (A), (B), (D)

The correct options are
A Distance between A & B' is equal to distance between A' & B
B Distance between A & B is less than distance between A' & B
D Distance between B & mirror is equal to distance between A & B

A plane mirror forms the image of an object such that both the object and the image are equidistant from the mirror. Here, A' is the image of A and B' is the image of B.

• Distance between A' & mirror is $2m$, so distance A & mirror is also $2m$.
• Distance between A & B is $1m$, so distance between A' & B' is also $1m$.
• Distance between A (or A') & mirror is $2m$, A & B is 1, so distance between B (or B') & mirror is $1m$.

Distance between B & mirror $=1m$
Distance between A & B' $=2+1=3m$
Distance between A' & B $=1+2=3m$
Distance between A & B $=1m$
Distance between B & B' $=1+1=2m$
Distance between A & A' $=2+2=4m$

Accordingly, correct options can now be easily chosen.