Physics
Physics
Problem
Two mirrors of equal size—one plane and the other convex—are used as rear-view mirrors on identical motorbikes at the same road junction. Which statement correctly explains why the rider using the convex mirror observes a larger field of view? a) Because the image formed by a convex mirror is always diminished, several objects can fit into the smaller image space, giving the impression of a wider view. b) Reflected rays from the convex surface diverge as if they come from a point behind the mirror, allowing the eye to receive light from a wider angular region. c) The negative focal length of a convex mirror makes the reflected rays converge earlier toward the axis, thereby spanning a larger scene. d) A convex mirror reflects a larger percentage of the incident light than a plane mirror, so more surroundings become visible.Intuitive explanation
A convex mirror curves outward, which spreads light rays apart before they reach your eye—this is the key to understanding its advantage. Because the mirror's surface diverges incoming rays, objects appear smaller and more compressed, allowing you to see a wider angular range of the road behind you compared to a flat mirror. The trade-off is that everything looks farther away, but you gain coverage of a much larger field of view, which is why convex mirrors are preferred for safety on vehicles.
Intuitive explanation
A convex mirror curves outward, which spreads light rays apart before they reach your eye—this is the key to understanding its advantage. Because the mirror's surface diverges incoming rays, objects appear smaller and more compressed, allowing you to see a wider angular range of the road behind you compared to a flat mirror. The trade-off is that everything looks farther away, but you gain coverage of a much larger field of view, which is why convex mirrors are preferred for safety on vehicles.