An object is placed 20 cm in front of a concave mirror of a radius of curvature 10 cm. The position of the image from the pole of the mirror is:

1. 7.67 cm

2. 6.67 cm

3. 8.67 cm

4. 9.67 cm

An object is at a distance of 30 cm in front of a concave mirror of focal length 10 cm. The image of the object will be:

1. smaller in size.

2. inverted.

3. between the focus and centre of curvature.

4. All of the above.

Match the corresponding entries of Column 1 with Column 2.
(Where m is the magnification produced by the mirror)

When a concave mirror of focal length f is immersed in water, its focal length becomes f', then:

1. f'=f

2. f'<f

3. f'>f

4. The information is insufficient to predict

A 4.5 cm needle is placed 12 cm away from a convex mirror of focal length 15 cm. What is the magnification?

1. 0.5

2. 0.56

3. 0.45

4. 0.15

A concave mirror gives an image three times as large as the object placed at a distance of 20 cm from it. For the image to be real, the focal length should be:

1. 10 cm

2. 15 cm

3. 20 cm

4. 30 cm

A convex mirror of focal length f forms an image which is \(1 \over n\) times the length of the object. The distance of the object from the mirror is:

1. (n-1)f

2. \(({n-1 \over n})f\)

3. \(({n+1 \over n})f\)

4. (n+1)f

A thin rod of length f/3 lies along the axis of a concave mirror of focal length f. One end of its magnified, real image touches an end of the rod. The length of the image is:

1. f

2. $\frac{1}{2}f$

3. 2f

4. $\frac{1}{4}f$

A rod of length 10 cm lies along the principal axis of a concave mirror of focal length 10 cm in such a way that its end closer to the pole is 20 cm away from the mirror. The length of the image is:

1. 10 cm

2. 15 cm

3. 2.5 cm

4. 5 cm

The distance between the object and its real image formed by a concave mirror is minimum when the distance of the object from the centre of curvature of the mirror is: [f $\to$ focal length of the mirror]

1.  Zero

2.  $\frac{\mathrm{f}}{2}$

3.  f

4.  2f