Question

A person has been using spectacles of power $-1.0$ dioptre for distant vision and a separate reading glass of power $2.0$ dioptres What is the least distance of distinct vision for this person :

• A. 10 Cm
• B. 40 Cm
• C. 30 Cm
• D. 50 Cm

Answer 1

Answer: (D)

50 Cm

Answer 2

The correct option is(D): 50cm

$\frac{!}{v}-\frac{1}{u}=\frac{1}{f^{'}}$
P=2D=2m-1
$\frac{1}{f}=\frac{2}{100}cm^{-1}$
$\frac{1}{V}-(-\frac{1}{25})=\frac{2}{100}$
$\frac{1}{V}=\frac{1}{50}-\frac{1}{25}$

V=-50 cm