A device that converts sound energy into electrical energy is?
the horn of a motor car
an A.C. generator
a microphone
the telephone
radio waves
Correct answer is C
The dynamic microphone is constructed with a small magnet that oscillates inside a coil attached to the diaphragm.
When a sound wave causes the diaphragm of the microphone to vibrate, the relative motion of the magnet and coil creates an electrical signal by magnetic induction.
The spectrum of white light consists of coloured lights arranged in the following order
blue, red, green, yellow, indigo, violet, orange
red, orange, yellow, green, blue, indigo, violet
red, orange, yellow, indigo, green, blue, violet
indigo, green, blue, violet, yellow, red, orange
yellow, blue, green, violet, orange, indigo, red
Correct answer is B
No explanation has been provided for this answer.
What is the apparent colour of a RED SHIRT when viewed in PURE green light?
Red
Green
Yellow
Black
Blue
Correct answer is D
When green light is shone on a red object, it absorbs all of the green light and not reflecting anything. Hence, it appears black.
0%
25%
75%
300%
400%
Correct answer is C
P2V2T2 = P1V1T1
P2 = 2P1
T1 = 2T2
2P1V2T2 = P1V12T1
V2 --V1
% change = V1−14V1V1 X 100%
= 75%