Question

1.An object position and image position coincide at 20 cm from a concave mirror. It's focal length is
20cm
-20cm
10cm
-10cm

2. On a 1 m scale, a concave mirror of focal length 10 cm is placed at middle. A candle flame is placed in front of the reflecting face of mirror at 20cm mark of the scale. Where on the scale should a screen be placed to get image of the screen?
At 35 cm mark of scale
At 15 cm mark of scale
At 7.5 cm mark of scale
At 20 cm mark of scale

3. An object is placed at 10 cm in front of a concave mirror of radius of curvature 20 cm. The image position is
0
infinity
-5cm
5cm

4.The image of Sun is formed by a mirror of radius of curvature 50 cm. The nature of mirror and position of image is
concave -50cm
convex 50cm
convex 25cm
concave -25cm

5.An object is kept at 4cm facing the concave side of a shiny silver spoon . A real image is formed at 4/3cm from its pole. Then the concave side is turned sideways such that convex mirror of the spoon now faces the object. The image distance now is ( assume that the object to pole distance remains same for convex mirror case)
-4/3
4/3
4/5
5/4

6.The focal length of a concave mirror is 10 cm. One half of the reflecting surface of the mirror is waxed. Then the new focal length is
10cm
5cm
20cm
data is insufficient

7.A virtual, erect and magnified image of an object is produced for a concave mirror of focal length 12cm . Which of the following object distance should be chosen for this purpose
12cm
10cm
24cm
48cm

8.At what distance from a concave mirror of focal length 10cm should an object 2cm long be placed in order to get an erect image 6cm tall?
-6.6cm
+6.6cm
-6.4cm
+6.4cm

9.A converging mirror forms a real image of height 4cm of an object of height 1 cm placed 20 cm away from the mirror. Calculate the image distance ?
40cm
-40cm
-80cm
-20cm

10.An object placed 20cm in front of a mirror is found to have an image 15cm behind the mirror , Find the focal length and the type of mirror
-8.5cm ,concave mirror
60cm,convex mirror
+8.5cm ,convex mirror
-60cm ,concave mirror​

Answer 1

1. a

2.d

3.c

4.b

5.c

6.d

7.a

8.a

9.c

10.b