Question 16 of 31intermediate🔧 ApplyMCQ1 mark

An electric bulb is rated 220 V and 100 W. When it is operated on 110 V, the power consumed will be –

Exercise: EXERCISES | Q: 3 | (Page Page 23)
For More Understanding

Explanation

Option D is correct. The power consumed by an electric bulb depends on the voltage applied and its resistance. Using the formula P = V²/R from the textbook, we first calculate the resistance of the bulb from its rated values, then determine the power consumed at the lower voltage.

Solution Steps

  1. Step 1: From the formula P = V²/R, calculate the resistance of the bulb using rated values: R = V²/P = 220²/100 = 48400/100 = 484 Ω

  2. Step 2: When operated at 110 V, calculate the new power consumed: P = V²/R = 110²/484 = 12100/484 = 25 W

  3. Step 3: The power consumed at 110 V is 25 W, which corresponds to option (D)

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