CUET · PHYSICS · PYQ PAPER 2025
A metal cube of side 0.1 m is uniformly charged by 18 \( \mu C \). Its surface charge density will be
- A \( 18.8 \times 10^{-4} \, C \, m^{-2} \)
- B \( 18 \times 10^{-3} \, C \, m^{-2} \)
- C \( 3 \times 10^{-4} \, C \, m^{-2} \)
- D \(3 \times 10^{-3} \, C \, m^{-2} \)
Answer & Solution
Correct Answer
(C) \( 3 \times 10^{-4} \, C \, m^{-2} \)
Step-by-step Solution
Detailed explanation
\( A = 6 L^2 = 6 (0.1 \, m)^2 = 0.06 \, m^2 \) \( \sigma = \frac{Q}{A} = \frac{18 \times 10^{-6} \, C}{0.06 \, m^2} = 3 \times 10^{-4} \, C \, m^{-2} \)
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