Optics Question 676
Question: A film projector magnifies a 100 cm2 film strip on a screen. If the linear magnification is 4, the area of magnified film on the screen is
[NCERT 1980; CPMT 1977, 91; MP PET 1985, 89; RPMT 2001; BCEC 2005]
Options:
A) 1600 cm2
B) 400 cm2
C) 800 cm2
D) 200 cm2
Show Answer
Answer:
Correct Answer: A
Solution:
$ m _{L}=4 $
$ m _{A}={{(m _{1})}^{2}} $ so that
$ \Rightarrow dv=-{{( \frac{v}{u} )}^{2}}du $
