Question

If three tube lights with power 10 W, 25 W and 50 W are connected in parallel to a source voltage V, then the effective power of the combination is

• A. 8 W
• B. 85 W
• C. 28.3 W
• D. 50 W
• E. 6.25 W

Hint:

In series, the effective power is calculated like parallel resistors: \( \frac{1}{P_{\text{eff}}} = \frac{1}{P_1} + \frac{1}{P_2} + \frac{1}{P_3} \).
In parallel, it is simple addition.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
When electrical appliances are connected in parallel, the total power consumed is the sum of the individual powers of each appliance.

Step 2: Key Formula or Approach:
For parallel combination:
\[ P_{\text{total}} = P_1 + P_2 + P_3 + \dots \]

Step 3: Detailed Explanation:
Given power ratings:
\( P_1 = 10 \text{ W} \)
\( P_2 = 25 \text{ W} \)
\( P_3 = 50 \text{ W} \)
Calculating effective power:
\[ P_{\text{eff}} = 10 + 25 + 50 = 85 \text{ W} \]

Step 4: Final Answer:
The effective power of the combination is 85 W.