You need to select a laptop for a traveling salesman. He will really need to stretch the battery life as
long as possible, so he wants low power
options wherever possible. Which type of monitor should you select?

A.
LCD

B.
CRT

C.
Active Matrix

D.
Passive Matrix

Explanation:

Passive matrix LCD monitors use less power than active matrix, and are generally preferred for
laptops when long battery life is the key
concern.
Answer option C is incorrect. An active matrix LCD uses more power than a passive matrix, but gives
a higher quality picture.
Answer option B is incorrect. Cathode Ray Tube monitors are legacy monitors that were once used
on PC’s.
Answer option A is incorrect. All laptops use LCD monitors. The question is whether or not one
should select an active or passive matrix LCD.
What is Cathode Ray Tube (CRT)? Hide
Cathode Ray Tube (CRT) is a vacuum tube used as a display screen in a computer monitor or TV. The
viewing end of the
tube is coated with phosphors, which emit light when struck by electrons. CRT works by heating a
cathode which causes
electrons to flow. Accelerating and focusing anodes turn the electrons into a fine beam that is
directed to the phosphors by
magnetic fields that are generated by steering coils. The viewing end of a color CRT tube is coated
with red, green and blue

phosphor dots, and separate “electron guns” bombard their respective colors a line at a time in a
prescribed sequence.
The resulting color displayed on screen is determined by the intensity of the electron beams as they
strike the red, green
and blue phosphors at that same pixel location.