If the image formed by a convex mirror of focal length 30 cm is a quarter of the size

If the image formed by a convex mirror of focal length 30 cm is a quarter of the size of the object, then the distance of the object from the mirror will be

Options

(a) 30 cm
(b) 60 cm
(c) 90 cm
(d) 120 cm

Correct Answer:

90 cm

Explanation:

Given, f = + 30 cm and m = 1 / 4 Magnification, m = f / (f – u)

Therefore, 30 / (30 – u) = 1 / 4

30 – u = 120

⇒ u = -90 cm

admin:

Related Questions

  1. Pure Si at 300 k has equal electrons (nₑ) and hole (nh) concentrations
  2. An object is placed 30 cm away from a convex lens of focal length 10 cm and a sharp
  3. An explosion breaks a rock into three parts in a horizontal plane
  4. A parallel plate air capacitor has capacity C, distance of seperation between plate
  5. Identify the paramagnetic substance