The battery of a mobile phone is rated as 4.2 V, 5800 mAh. How much energy is stored in it when fully charged? (a) 87.7 kJ (b) 43.8 kJ (c) 48.7 kJ (d) 24.4 kJ

Answer: (a). Charge q = 5800 mAh = 5.8 × 3600 = 20880 C. E = Vq = 4.2 × 20880 ≈ 87696 J. So the answer is (a) 87.7 kJ.

The battery of a mobile phone is rated as 4.2 V, 5800 mAh. How much… | JEE Main 2025 (2 Apr, Shift 1)

Q7JEE Main 2025 · 2 APR · SHIFT 1Medium

Electrical Power & Heating Effect

The battery of a mobile phone is rated as $4.2\text{ V},\ 5800\text{ mAh}$ . How much energy is stored in it when fully charged?

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Answer: (a)

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