Question

A 20 W bulb connected to a battery draws a current of 2 Amperes. Find the resistance of its filament and the potential difference across its terminals​

Answer 1

Answer:

Resistance = 2 ohms

Explanation:

Answer 2

Answer:

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Resistance of its filament is 5Ω and the potential difference across its terminals is 10 volts.

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Explanation:

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Given:

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• P = 20 W

• I = 2 A

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where P is Power and I is Current.

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To find:

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Resistance of its filament and the potential difference across its terminals.

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Solution:

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P = I$^{2}$ × R

So by using this formula, first we will find resistance.

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Substitute the known values, we get

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20 = 2 × 2 ×

$⇒R = \frac{20}{2 \times 2}$

⇒ R = 5Ω

Now, we know that:

P = I × V

Substitute the known values, we get

20 = 2 × V

⇒ V = 20/10

⇒ V = 10 volts

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Thus, resistance is 5Ω and potential difference is 10 volts.