Reflection of Light

Q.

A thick plane mirror shows a number of images of the filament of an electric bulb. Of these, the brightest image is the

1. First

2. Second

3. Fourth

4. Last

Q. A mirror is inclined at an angle $\theta$ with the horizontal and a ray of light is incident on it as shown. Find the angle made by the reflected ray with the horizontal.

1. $\theta$
2. $2\theta$
3. $\theta /2$
4. Zero

Q.

A ray of light is incidenting normally on a plane mirror. The angle of reflection will be

1. 

2. 
3. Will not be reflected

4. None of the above

Q. If the incident ray is stationary, but the plane mirror rotates by an angle of ${30}^{\circ }$, then the reflected ray gets rotated by .

1. ${60}^{\circ }$
2. ${30}^{\circ }$
3. ${90}^{\circ }$
4. $0^{\circ }$

Q. Two plane mirrors are inclined at angle $\theta$ as shown in figure. If a ray parallel to $OB$ strikes the other mirror at $P$ and finally emerges parallel to $OA$ after two reflections, then $\theta$ is equal to

1. ${90}^{\circ }$
2. ${60}^{\circ }$
3. ${45}^{\circ }$
4. ${30}^{\circ }$

Q. Two plane mirrors are inclined at an angle $\theta$ as shown in the figure. Find the value of $\theta$ such that the light ray retraces its path after second reflection.

1. ${30}^{\circ }$
2. ${60}^{\circ }$
3. ${45}^{\circ }$
4. ${75}^{\circ }$

Q. Two plane mirrors are inclined at angle $\theta$ as shown in figure. If a ray parallel to $OB$ strikes the other mirror at $P$ and finally emerges parallel to $OA$ after two reflections, then $\theta$ is equal to

1. ${90}^{\circ }$
2. ${60}^{\circ }$
3. ${45}^{\circ }$
4. ${30}^{\circ }$

Q. Two plane mirrors each $14\text{m}$ long are facing each other as shown in the figure. The distance between the mirrors is $\sqrt{3}\text{m}$. A light ray is incident at the corner end of one of the mirrors at an angle of incidence ${30}^{\circ }$. How many times does the ray gets reflected before it reaches the other corner end of the either mirrors?

1. $14$
2. $10$
3. $12$
4. $18$

Q. Identify the incorrect statement regarding the reflection of light from a plane mirror when a light ray is incident obliquely. $\overrightarrow{R},\overrightarrow{I}$ and $\overrightarrow{N}$ represents the vectors along the reflected ray, incident ray and normal direction.

1. $\overrightarrow{R}.(\overrightarrow{I}\times \overrightarrow{N})=0$
2. $\overrightarrow{N}.(\overrightarrow{I}\times \overrightarrow{R})=0$
3. $\overrightarrow{I}.(\overrightarrow{N}\times \overrightarrow{R})=0$
4. $\overrightarrow{N}\times \overrightarrow{I}=0$

Q. ${\hat{n}}_1$ is the unit vector along incident ray, ${\hat{n}}_2$ along the normal to plane mirror and $\widehat{n_3}$ is the unit vector along reflected ray direction, then which of the following must be true?

1. ${\hat{n}}_1.{\hat{n}}_2=0$
2. ${\hat{n}}_1.{\hat{n}}_3=0$
3. $({\hat{n}}_1\times {\hat{n}}_2).{\hat{n}}_3=0$
4. $({\hat{n}}_1\times {\hat{n}}_2)\times {\hat{n}}_3=0$

Q.

When light wave suffers reflection at the interface from air to glass, the

change in phase of the reflected wave is equal to

[CPMT 1991; J & KCET 2004]

1. \N

2. 

3. 

4.