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GUJCET · Physics · Electric Charges and Fields
A polythene piece rubbed with wool is found to have a negative charge of \(3.52 \times 10^{-7} C\). What is the number of electrons transferred ?
- A \(1.1 \times 10^{12}\)
- B \(2.2 \times 10^{12}\)
- C \(4.4 \times 10^{12}\)
- D \(5.5 \times 10^{12}\)
Answer & Solution
Correct Answer
(B) \(2.2 \times 10^{12}\)
Step-by-step Solution
Detailed explanation
(B)
\(\begin{array}{ll}\text { Charge } & q=n e \\ \therefore & n=\frac{q}{e} \\ \therefore & n=\frac{3.52 \times 10^{-7}}{1.6 \times 10^{-19}} \\ \therefore & n=2.2 \times 10^{12} \text { electrons }\end{array}\)
\(\begin{array}{ll}\text { Charge } & q=n e \\ \therefore & n=\frac{q}{e} \\ \therefore & n=\frac{3.52 \times 10^{-7}}{1.6 \times 10^{-19}} \\ \therefore & n=2.2 \times 10^{12} \text { electrons }\end{array}\)
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