A convex lens power is 4d is placed at a distance of 40 cm from a wall. At what distance from the lens should a candle be placed so the image is formed on the wall
Answers
Answered by
1
By placing it at 50 cm away
Answered by
3
Reciprocal of focal length expressed in metres is
called power. SI unit is dioptre.
Main Part:
f = 1/P
f = 1/4D
f = 1/4m
f = 25cm
v = 40m
NOW
=> 1/v -1/u = 1/f
=> 1/u = 1/v - 1/f = -3/200
=> u = -200/3cm
Therefore,
Candle should be placed 200/3 cm from the lens.
Similar questions