1. 1.28×10⁴ N/C 2. 1.28×10⁵ N/C 3. 1.28×10⁶ N/C 4. 1.28×10⁷ N/C

A spherical conductor of radius 10 cm has a charge of 3.2×10^-7 C distributed uniformly. What is the magnitude of electric field at a point 15 cm from the centre of the sphere ?≤ft(1/4πε_0 = 9×10^9\ N m^2/C^2)

1. $1.28\times10^4$ N/C

2. $1.28\times10^5$ N/C

3. $1.28\times10^6$ N/C

4. $1.28\times10^7$ N/C

Doubtly Asked 30 Oct 2026 NEET UG 2020 Practice test neet Save WhatsApp Report

Best answer

Answer: 2. $1.28\times10^5$ N/C

Outside a uniformly charged sphere, the field is the same as that of a point charge at the centre.

$$E=\frac{1}{4\pi\epsilon_0}\frac{Q}{r^2}=\frac{9\times10^9\times3.2\times10^{-7}}{(0.15)^2}=\frac{2880}{0.0225}=1.28\times10^5\ \text{N/C}$$

Answer: option 2.

Doubtly AI · 30 Oct 2026 AI-generated · not yet verified Report

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