Mirror Formula

Q.

A $4.5cm$ needle is placed at $12cm$ away from a convex mirror of a focal length of $15cm$ Give the location of the image and the magnification. Describe what happened as the needle is moved further from the mirror.

Q. An object is placed at a distance 2f from the pole of a convex mirror of focal length f. Themagnification is

Q. According to mirror formula, the correct relation between the image distance $\left(v\right)$, object distance $\left(u\right)$ and the focal length $\left(f\right)$ is:

1. $\frac{1}{v}+\frac{1}{u}=-\frac{1}{f}$
2. $\frac{1}{v}+\frac{1}{u}=\frac{1}{f}$
3. $\frac{1}{v}+\frac{1}{f}=\frac{1}{u}$
4. $\frac{1}{v}+\frac{1}{f}=-\frac{1}{u}$

Q.

If we say that the focal length of a spherical mirror is n times its radius of curvature, then n must be

1. $1.5$

2. $0.2$

3. $2.0$

4. none of these

Q. An object looks red when seen through a piece of red glass. What is the actual colour of the object? (1)Red only (2)White only (3)Red or green (4)Black

Q.

What is the relation between the radius of curvature and the focal length of the spherical mirror?

Q. An object of length $4cm$ is placed in front of a concave mirror at a distance of $30cm$. The focal length of mirror is $15cm$. Where will the image form?

1. $15cm$ behind the mirror.
2. $15cm$ in front of mirror.
3. $30cm$ behind the mirror.
4. $30cm$ in front of mirror.

Q.

Draw a ray diagram to show the formation of image by a concave mirror for the object beyond its centre of curvature. State three characteristics of the image.

Q. Why concave mirror forms a real and inverted image of an object placed on focus.Why not virtual and erect?

Q. Identify the ray diagram that shows the formation of an image by a plane mirror.

1. 
2. 
3. 
4. 

Q. STATEMENT-1: The formula connecting u, and f for a sphericalmirror is valid only for those mirrors whose sizes are very smallcompared to their radii of curvature.STATEMENT-2: The laws of reflection are strictly valid for planesurfaces but not for large spherical surfaces.(a) Statement-1 is True, Statement-2 is True; Statement-2 is acorrect explantion for Statement-1(b) Statement-1 is True, Statement-2 is True; Statement-2 isnot a correct explanation for Statement-1.(c) Statement-1 is True, Statement-2 is False.(d) Statement-1 is False, Statement-2 is True.

Q. A gun of mass $m_1$ fires a bullet of mass $m_2$ with a horizontal speed $v_0$. The gun is fitted with a concave mirror of focal length $f$ facing toward a receding bullet. Find the speed of separations of the bullet and the image just after the gun was fired.

Q.

what is principle focus

Q. A person 1.4 m in front of a plane mirror seems to be _______________ m away from his image in the mirror.

1. $1.4$
2. $2$
   
3. $2.8$
   
4. $3$
   

Q.

An object is placed in front of a convex mirror at a distance of 60m from its pole. Object starts moving towards the mirror at 20 $\frac{m}{s}$. Find the average velocity of the image for a time interval of 2 sec if the focal length of the mirror is 20m.

1. 20 m/s

2. 10 m/s

3. 30 m/s

4. None of the above

Q. In a plane mirror, an object is 0.5 m in front of the mirror. The distance between object and image is -

1. 1 m
2. 0.5 m
3. 0.25 m
4. 0.75 m

Q. Pl show the area of aperture in sperical mirror. What is meant by intensity of image is proportional to area of aperture