Question

A ceiling fan operates at three speeds, using 120 V of electricity from the wall. At low speeds, it uses 0.25 A. Calculate the resistance needed to generate that current. Then in 1-2 sentences, describe how the resistance would change at medium and high speeds if larger currents are needed at those speeds. Your answer should include the calculated resistance and a sentence describing your reasoning.

Answer 1

Ohm's law describes the relations among voltage, current and resistance. So that:

i. The resistance needed to generate the given current is 480 Ohm's.

ii. At medium speed, the resistance decreases while the current increases.

iii. The high speed requires large current but least resistance.

Ohm's law states that:  V = IR

where V is the voltage, I is the current and R is the resistance.

Thus from the given question, V = 120 V, and A = 0.25, so that:

R = $\frac{V}{I}$

  = $\frac{120}{0.25}$

R = 480 Ohm's

Therefore, the resistance required to generate a current of 0.25 A at low speed is 480 Ohm's.

Ohm's law explains that the voltage is proportional to current so that to generate greater amount of current, low resistance is required. Thus, at the medium speed, more current would be required so that the value of resistance to produce the current would be lesser than that at the low speed.

At higher speed, the value of resistance would reduce far below that attained in medium speed, so that more current would be produced. Thus the high speed requires large current but low resistance.

See more about the application of Ohm's law at: https://brainly.com/question/10566593

Answer 2

The answer is 480Ω.

According to Ohm's Law, the required equation to find resistance is :

$\boxed {R = \frac{V}{I}}$

Then, by direct substitution, we get :

• R = 120 V ÷ 0.25 A
• R = 480Ω

For medium and higher speeds, the resistance would have to decrease in order to allow for more current to reach the fan. For it to operate at the necessary speeds, the resistance would have to be less than 480Ω.