Question

Four students A,B,C and D did their experiment of finding the focal length of convex
lens by obtaining image of a distant object as follows:
 Student A used the window grill in the laboratory as the object and a white
paper sheet held in hand as the screen.
 Student B used a distant tree in the shade and a white thick held in a stand
as the screen.
 Student C used a well illuminated laboratory window grill as the object and a
white paper sheet held in a stand as the screen.
 Student D used a well illuminated distant tree as the object and a white thick
board held in a stand as the screen.
Which student has used the correct method for performing experiment out of the
above setups?
(a) A (b) B (c) C (d) D

Answer 1

Here Four students named A,B,C,D perform experiment of finding focal length of given convex lens by distant object method.

Student A used : window grill in the laboratory as the object and a whitepaper sheet held in hand as the screen.

Student B:a distant tree in the shade and a white thick held in a stand

student C: a well illuminated laboratory window grill as the object and a white paper sheet held in a stand as the screen.

Student D:well illuminated distant tree as the object and a white thick board held in a stand as the screen.

As we want bright rays coming from distant object we select the option D- student D method of experiment is correct.

Reason: Student A method will not be called as distant object method.
student B light rays will be not bright
Student C - It cannot be distant object method.

Hence correct option ----D

Answer 2

Answer:

D is the correct answrr