Which one of the following types of electromagnetic radiation causes certain substances to fluoresce?
a. cosmic rays
b. ultraviolet rays
(c. x rays)
d. infrared waves
a virtual image produced by a lens is always
a. located in front of the lens.
(b. located in the back of the lens.)
c. smaller than the object.
d. larger than the object.
reflecting telescopes are popular because they're
a. more durable than a refracting telescope.
b. more powerful than a refracting telescope.
c. easier to build than a refracting telescope.
(d. smaller than a refracting telescope.)
the unit for measuring the rate at which light energy is radiated from a source is the
a. lux.
b. lumen.
(c. candela.)
d. angstrom
a magnifying glass is an example of a lens.
a. plano-concave
(b. plano-convex)
c. double-concave
d. converging
my answer is in ( ) and the answers are wrong tell me the correct answer because i dont have a clue