Answer:
<h2><u>Rheostat:</u></h2>
=> Rheostat is an electric device used as a variable resistance, like the regulator of the fan. It is used to change the electric resistance in the electric circuit.
<h2><u>Principle / Rule:</u></h2>
=> Rheostat works on the principle of Ohm’s law. Ohm’s law states that current in a circuit is inversely proportional to the resistance at the given temperature.

Volume isn't a property of matter at all. You can have a big lump or a tiny lump of the same substance.
Answer:
73.52983 Hp
Explanation:
m = Mass of car = 
W = Weight of car = 12000 N
a = Acceleration = 0.96 m/s²
Velocity of the car

From the question

Balancing the forces

The power is 73.52983 Hp
B) low energy, because red is on the far left of the electromagnetic spectrum.