Question 5 of 25 Which of the following means that a mirror is convex?
A. +d;
B. -d;
O C. +f
O D. -f

Option (c) : +f

Explanation:

Sign convention is based on cartesian system with Optical Centre as vertex, therefore, focal length of a convex mirror is +ive.

shows up as a (purple)/ (flashing) red or blue dot getting bigger and brighter.

explanation:

luster is not a good characteristic to use by itself because luster is the property of minerals that indicates how much the surface of a mineral reflects light. the luster of a mineral is affected by the brilliance of the light used to observe the mineral surface.