Question

An electrical appliance is rated 1500 W, 250 V. This appliance is connected to a 250 V supply mains. The current drawn by the appliance (assuming unity power factor) is:

• A. 16 A
• B. 6 A
• C. 15 A
• D. 12 A

Hint:

Power is the product of voltage and current for resistive loads. For a rated appliance, simply divide the power by the voltage to find the current.

Answer 1

The Correct Option is B

To determine the current drawn by the appliance, we use the power formula: \( P = V \times I \), where:

• \( P \) is the power in watts (W)
• \( V \) is the voltage in volts (V)
• \( I \) is the current in amperes (A)

Given:

• \( P = 1500 \, \text{W} \)
• \( V = 250 \, \text{V} \)

Plugging these values into the formula, we solve for \( I \):

\[ I = \frac{P}{V} \]

\[ I = \frac{1500}{250} \]

\[ I = 6 \, \text{A} \]

Hence, the current drawn by the appliance is 6 A.

Answer 2

The appliance is designed to draw 1500 W when connected to 250 V, and it is now connected to exactly that same 250 V supply, so at unity power factor the current it draws must satisfy \(V\times I = 1500\,\text{W}\). Each option is checked by multiplying it by the 250 V supply to see which one reproduces the rated 1500 W.

1. Option A (16 A): \(250\times16=4000\,\text{W}\), far above the 1500 W rating.
2. Option B (6 A): \(250\times6=1500\,\text{W}\), exactly the rated power of the appliance.
3. Option C (15 A): \(250\times15=3750\,\text{W}\), well above the 1500 W rating.
4. Option D (12 A): \(250\times12=3000\,\text{W}\), double the rated power.

Only option B reproduces the appliance's rated power when multiplied by the 250 V supply.

Hence, the correct answer is 6 A.