JEE Main2018PhysicsRay OpticsActual
A particle is oscillating on the x -axis with an amplitude 2 cm about the point x 0 = 10 cm with a frequency. A concave mirror of focal length 5 cm is placed at the origin (see figure). Identify the correct statements? (i) The image executes periodic motion. (ii) The image executes non-periodic motion. (iii) The turning points of the image are asymmetric with respect to the image of the point at X = 10 cm . (iv) The
Options
- A(ii, iii)
- B(i, iii, iv)
- C(i, iv)
- D(ii, iv)
Correct answer
B. (i, iii, iv)
Step-by-step solution
Recall the proper formula of mirror formula, 1 f = 1 v + 1 u , given f = - 10   cm and u = - 5   cm then the formula of the concave mirror, - 1 10 = 1 v - 1 5 ⇒ v = - 10   cm . As, image copies the time period of the object A is right as well. It will be a periodic motion. For one extreme, ⇒ - 1 8 + 1 v = 1 - 5 ⇒ v = - 40 3   cm , right arrow. For other extreme, ⇒ - 1 12 + 1 v = 1 - 5 ⇒ v = - 7 60   cm . These points are asymmetrical about x 0 = 10   cm .