Magnification

Q. A mirror produces a virtual image four times enlarged of a boy standing $2.5\text{m}$ away from it. The type of mirror and its radius of curvature will be

1. Convex, $3.33\text{m}$
2. Convex, $6.67\text{m}$
3. Concave, $3.33\text{m}$
4. Concave, $6.67\text{m}$

Q. For the arrangement shown in the figure, find the final magnification of the extended object $AB$ after two successive reflections. Take the first reflection from mirror $M_1$.

1. $+1$
2. $+2$
3. $-1$
4. $-2$

Q.

An object of size 7.5cm is placed in front of a convex mirror of radius of curvature 25cm at a distance of 40cm The size of the image should be

1. 2.3cm
2. 1.78cm
3. 1cm
4. 0.8cm

Q. A $\text{U}-$ shaped wire $abcd$ of length $30\text{cm}$ is placed before a concave mirror having radius of curvature $20\text{cm}$. Find the total length of the image of wire.

1. $11\text{cm}$
2. $10\text{cm}$
3. $12\text{cm}$
4. $14\text{cm}$

Q. When an object is placed at a distance of $25\text{cm}$ from a mirror, the magnification is $m_1$. But the magnification becomes $m_2$ when the object is moved $15\text{cm}$ farther away from the mirror with respect to earlier position. If $\frac{m_1}{m_2}=4$, then find the focal length of the mirror and its nature.

1. $20\text{cm}$, convex
2. $20\text{cm}$, concave
3. $10\text{cm}$, convex
4. $10\text{cm}$, concave

Q.

The focal length of a concave mirror is f and the distance from the object to the principle focus is x. The ratio of the size of the image to the size of the object is
[Kerala PET 2005]

1. 
2. 
3. 
4. 

Q.

The image is inverted when:

1. The magnification is positive

2. The magnification is negative

3. The orientation of the image has nothing to do with the sign of the magnification

4. Can not comment

Q. A mirror produces a virtual image four times enlarged of a boy standing $2.5\text{m}$ away from it. The type of mirror and its radius of curvature will be

1. Convex, $3.33\text{m}$
2. Convex, $6.67\text{m}$
3. Concave, $3.33\text{m}$
4. Concave, $6.67\text{m}$

Q. For the arrangement shown in the figure, find the final magnification of the extended object $AB$ after two successive reflections. Take the first reflection from mirror $M_1$.

1. $+1$
2. $+2$
3. $-1$
4. $-2$

Q. A wire is bent into square shape of side $3\text{cm}$ and placed at $25\text{cm}$ in front of a concave mirror of focal length $10\text{cm}$ with one of its edge on the principal axis of the mirror and its plane normal to the axis. The area enclosed by the image of the wire will be

1. $6{\text{cm}}^2$
2. $5{\text{cm}}^2$
3. $4{\text{cm}}^2$
4. $7{\text{cm}}^2$