A lens which is thicker at center and thinner at edges is MCQ with Answer and Explanation

Explanation:
The power (P) of a lens indicates its converging or diverging ability. It is mathematically defined as the reciprocal of the focal length (f), provided the focal length is measured in meters. The formula is P = 1 / f(in meters). The SI unit of power for a lens is the Diopter (D). A focal length of 0.5m gives a power of 2D.

Explanation:
The magnetic Lorentz force on a moving charge is F = q(v x B) = qvBsin(theta). If the particle moves completely parallel to the magnetic field, the angle theta is 0 degrees. Since sin(0) = 0, the magnetic force is absolutely zero. Experiencing no transverse force, the particle continues moving in a perfect straight line.

Explanation:
Iris adjusts pupil size. In bright light pupil constricts, dim light dilates. Retina forms image. Cornea and lens focus. Eye is like camera.