Q128 / 180 · NEET 2016 (Phase 1) · Physics

Match the corresponding entries of column 1 with column 2. [Where m is the magnification produced by the mirror]

Column 1 Column 2

(A) $m = - 2$ (a) Convex mirror

(B) $m = - \frac{1}{2}$ (b) Concave mirror

(C) $m = + 2$ (c) Real image

(D) $m = + \frac{1}{2}$ (d) Virtual image

Correct answer
A
A $\to$ b and c; B $\to$ b and c; C $\to$ b and d; D $\to$ a and d
B
A $\to$ a and c; B $\to$ a and d; C $\to$ a and b; D $\to$ c and d
C
A $\to$ a and d; B $\to$ b and c; C $\to$ b and d; D $\to$ b and c
D
A $\to$ c and d; B $\to$ b and d; C $\to$ b and c; D $\to$ a and d

Solution

m = \frac{- V}{u} = \frac{f}{f - u}

m = - 2

then "V" and "u" same given

- 2 = \frac{f}{f - u} =- 2 f + 2 u = f

= 3 f = 2 u

\frac{+ 3 f}{2} = u

For the concave mirror, f negative, u negative use same for all.

Hence, the correct answer is option: 'A'.