MCQs on Mirror Formula

MCQs on Mirror Formula

Q1: A convex mirror of focal length f forms an image which is 1/n times the object. The distance of the object from the mirror is

1. (n-1)f
2. (n-1/n) f
3. (n+1/n) f
4. (n+1) f

Answer: (a) (n-1)f

Q2: Consider a concave mirror of focal length 50 cm. Where should the object be placed so that its image is twice the size of the object and inverted

1. 60 cm
2. 70 cm
3. 75 cm
4. 55 cm

Answer: (c) 75 cm

Q3: An object 2 cm high is placed at a distance of 16 cm from a concave mirror, which produces 3 cm high inverted image. What is the focal length of the mirror?

1. -10 cm
2. -9.6 cm
3. 9.6 cm
4. 8 cm

Answer: (b) -9.6 cm

Q4: An erect image 3 times the size of the object is obtained with a concave mirror of radius of curvature 36 cm. What is the position of the object?

1. -12 cm
2. 5 cm
3. 10 cm
4. -21 cm

Answer: (a) -12 cm

Q5: An object is placed at infinity in front of the convex mirror of radius of curvature 40 cm. How far is the image behind the mirror?

1. 20 cm
2. 25 cm
3. 30 cm
4. 35 cm

Answer: (a) 20 cm

Q6: The image formed by a convex mirror of focal length 30cm is a quarter of the object. What is the distance of the object from the mirror?

1. -90 cm
2. 60 cm
3. -75 cm
4. -60 cm

Answer: (a) -90 cm

Q7: Convex mirror is used to form an image of the object. Which of the following statements is wrong?

1. The image is erect
2. The image is diminished in size
3. The image is real
4. The image lies between the pole and the focus

Answer: (c) The image is real

Q8: A lens having a focal distance of 30 cm is placed in front of an object, which is located at 1m from it. Where is an image of the object located?

1. 40 cm
2. 42.85 cm
3. 52 cm
4. 60 cm

Answer: (b) 42.85 cm

Q9: 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

1. (f + x)/f
2. f/x
3. f²/x²

Answer: (b) f/x

Q10: In a concave mirror experiment, an object is placed at a distance x₁ from the focus and the image is formed at a distance x₂ from the focus. The focal length of the mirror would be

1. x₁x₂
2. (x₁+x₂)/2
3. √x₁x₂
4. √x_1/x₂

Answer: (c) √x₁x₂