CLASS 10 CHAPTER 10 OBJECTIVE QUESTION ON LENS
1.
WHAT
IS THE UNIT OF LENS POWER
A.
METER B. DIPTEROUS C. CM D WATT
2.
ARRANGE
DECREASING ORDER OF REACTIVE INDEX OF WATER ,AIR , GLASS AND DIAMOND
A. WATER >AIR >GLASS >
B. WATER>GLASS >AIR >
C. DIAMOND > GLASS>WATER>AIR
D. DIAMOND >WATER> GLASS>AIR
3.
AN
OBJECT 25 CM HIGH IS PLACED IN FRONT OF A CONVEX LENS OF FOCAL LENGTH 30 CM .IF
THE HEIGHT OF IMAGE FORMED IS 50 CM , FIND THE DISTANCE BETWEEN OBJECT DISTANCE
AND IMAGE DISTANCE
A. 30 CM B.15 CM C.60 CM D. NONE OF THESE
4.
WHICH
LENS HAVE NEGATIVE FOCAL LENGTH
a. Convex lens
b.
concave lens c. concave
mirror d. none of these
5.
If focal
length of two lens are 10 cm , 20 cm then find combined focal length
a. 30 cm b. 20 cm c. 6.66 cm d. none of these
6.
An object
is placed at a distant of 1.50 m from a screen and a convex lens placed in
between produces an image magnified 4 time
on the screen . what is the focal and
the
position of the lens
a. 0.24 cm and 0.3 m
b. 0.4 cm and 0.24 m
c. 3 cm and 0.3 m
d. None of these
7.
An object
5 cm in length is held 25 cm away from a converging lens of focal length 10 cm
.position of image is
a. 16.7 cm b. 17 cm c.18 cm d.19 cm
8.
Which
lens always form erect image
a. Concave lens b. convex lens c. mirror d. none of these
9.
Define
power of lens ?
10.
what
plane mirror ?
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