Relation between Focal Length and Radius of Curvature

Q.

The radius of curvature of a convex mirror used on a moving automobile is $2\mathrm{m}$. A truck is coming behind it at a constant distance of $3.5\mathrm{m}$. Calculate the position and nature of the image.

Q.

If the image formed by a concave mirror is virtual, erect and magnified, then the object is placed:

1. At the centre of curvature

2. The nature of the image does not depend on the position of the object

3. Between the pole of the mirror and the focus

4. Beyond the centre of curvature

Q. When an object is placed between the centre of curvature and the focus of a concave mirror, its image will be:

1. virtual, erect and magnified.
2. virtual, erect and diminished.
3. real, inverted and magnified.
4. real, inverted and diminished.

Q. The minimum distance between the object and the image formed by a concave mirror can be:
(f is the focal length of the mirror)

1. Zero
2. f
3. 2f
4. 4f

Q. When an object is placed between the centre of curvature and the focus of a concave mirror, its image will be:

1. virtual, erect and magnified.
2. real, inverted and magnified.
3. real, inverted and diminished.
4. virtual, erect and diminished.

Q. When an object is placed between the centre of curvature and the focus of a concave mirror, its image will be:

1. real, inverted and diminished.
2. virtual, erect and magnified.
3. virtual, erect and diminished.
4. real, inverted and magnified.

Q.

If AB = 10 cm & DB = 40 cm (diameter). What is the radius of curvature & focal length of the spherical glass?

1. 20 cm, 20 cm

2. 40 cm, 10 cm

3. 40 cm, 5 cm

4. 20 cm, 10 cm

Q.

What is the relationship between the focal length f and radius of curvature R for a spherical mirror?

1. f = 2R

2. f = R

3. R = 2f

4. R = 4f

Q. An object kept at $20cm$ from a spherical mirror gives rise to an image $15cm$ behind the mirror. The focal length of the mirror is:

1. $-60cm$
2. $-30cm$
3. $60cm$
4. $90cm$

Q.

Which of the following relations hold good for 'R' and 'F', where 'R' is the radius of curvature of a spherical mirror and 'F' is the focal length of the mirror?

1. R = F

2. $R=\frac{F}{2}$

3. $F=\frac{R}{2}$

4. 2F = R

Q.

If the radius of curvature $\left(R\right)$ of a convex mirror is $30cm$. What is its focal length?

1. $30cm$

2. $60cm$

3. $15cm$

4. $10cm$

Q.

The radius of curvature of a concave mirror is 10 cm. If I want to capture the image of the sun, at what distance from the pole of the mirror would an image be formed?

1. 5 cm

2. 20 cm

3. At infinity

4. 10 cm

Q.

What is the relationship between the focal length f and radius of curvature R for a spherical mirror?

1. f = 2R

2. f = R

3. R = 2f

4. R = 4f

Q. In a concave mirror, when the object is at infinity, its image forms at

1. the focus
2. the Pole
3. the centre of curvature
4. infinity

Q. Distance between focus and centre of curvature is equal to .

1. height of the mirror
2. half of the radius
3. radius of curvature

Q.

If the radius of curvature $\left(R\right)$ of a convex mirror is $30cm$. What is its focal length?

1. $30cm$

2. $60cm$

3. $15cm$

4. $10cm$

Q.

The minimum distance between the object and the image formed by a concave mirror can be:
(f is the focal length of the mirror)

1. 2f

2. Zero

3. f

4. 4f