Reflection Test

Result

Reflection Test - 4

Score
-
out of -
Rank
-
out of -

TIME Taken - -

SHARING IS CARING

If our Website helped you a little, then kindly spread our voice using Social Networks. Spread our word to your readers, friends, teachers, students & all those close ones who deserve to know what you know now.

Weekly Quiz Competition

Question 1
1 / -0

A person AB of height 170 cm is standing in front of a plane mirror. His eyes are at height 164 cm. At what distance from P should a hole be made in the mirror so that he cannot see his hairs?

A
167 cm

B
161 cm

C
163 cm

D
165 cm

Solution

To see the image of hair, the rays incident from hair must reach the eye of the person after reflection.

Let the hole be made at a point M on the mirror where light coming from hair is reflected.

From the geometry of the diagram,
PM = BC
⇒ PM = BE + CE
Question 2
1 / -0

The figure shows two parallel plane mirrors placed 10cm apart. An object O is placed 7cm from mirror M₁. Then the distance of final image formed from mirror M₁ is

A
7cm

B
13 cm

C
14 cm

D
∞

Solution

Only M₁ is effective in making image since light rays will not fall on M₂
Question 3
1 / -0

A spherical concave mirror of focal length 10 cm is cut in two equal halves and is separated by a distance 4 mm as shown. A small object is kept at 30 cm from the mirrors and between the two halves as shown.

The distance between the images by halves of mirror will be

A
4 mm

B
6 mm

C
9 mm

D
12 mm

Solution
Question 4
1 / -0

A man is sitting in a room at 2 m from a wall W₁ wants to see the full height of the wall W₂ behind him 4 m high and 6 m away from the facing wall W₁. What is the minimum vertical length of mirror on the facing wall required for the purpose?

A
4 m

B
2 m

C
3 m

D
1 m

Solution

Let the min. length of mirror be L
Question 5
1 / -0

When a plane mirror is placed horizontally on a level ground at a distance of 60 m from the foot of a tower, the top of the tower and its image in the mirror subtend an angle of 90^o at the eye. The height of the tower will be

A
30 m

B
60 m

C
90 m

D
120 m

Solution
Question 6
1 / -0

A ray of light fails on a plane mirror. When the mirror is turned, about an axis which is at right angle to the plane of the mirror through 20^o the angle between the incident ray and new reflected ray is 45^o. The angle between the incident ray and original reflected ray was therefore:

A
65^o

B
25^o or 65^o

C
25^o

D
45^o

Solution

If mirror is turned, about an axis perpendicular to plane of mirror, then there will be no change in incident angle and reflected angle so angle between incident & reflected rays after rotation will be same as before.
Question 7
1 / -0

Find the distance between the object and its doubly magnified real image by a concave mirror of focal length f .

A
2f

B
3f/2

C
5f/2

D
3f

Solution
Question 8
1 / -0

The reflection surface of a plane mirror is vertical. A particle is projected in a vertical plane which is also perpendicular to the mirror. The initial velocity of the particle is 10 m/s and the angle of projection is 60⁰. The point of projection is at a distance 5m from particle moves towards the mirror . just before the particle touches the mirror. the velocity of approve of the particle and the image is :

A
10 m/s

B
5 m/s

C
10√3 m/s

D
5√3 m/s

Solution

Horizontal component of the velocity is 10cos(60)=5

And vertical component is 10sin(60) = 8.66

The participial will touch the mirror after = 5/5 = 1s

In this time vertical velocity will be V = u−gt = 8.66 − 9.8 × 1 = −1.14

Now the relative velocity will be due to horizontal component of the particle .

Since the vertical velocity will be same .

So, te relative velocity of the particle is 2 × 5 = 10m/s.
Question 9
1 / -0

The radius of curvature of a plane mirror of length 40 cm is:

A
20 cm

B
40 cm

C
0

D
None

Solution

The radius of curvature of a plane mirror is infinite.
Question 10
1 / -0

A rod 1.5 m long is placed along the principal axis of a convex mirror of focal length 60 cm. The near end of the rod is 1 m from the pole of the convex mirror. The length of the image of the rod is

A
15 cm

B
14.44 cm

C
6.62 cm

D
10.88 cm

Solution