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The number of fundamental (electronic) charges equivalent to a charge of 1 C is

Asked in GSEB Board July 2023 · Properties of charge

• (1) 6.25×10⁻¹⁹
• (2) 6.25×10¹⁹
• (3) 6.25×10⁻¹⁸
• (4) 6.25×10¹⁸

Step-by-step solution

Why the other options are wrong

• (1) A count of charges in a whole coulomb must be enormous, not a tiny fraction. No single slip gives 6.25×10⁻¹⁹: it has the exponent's sign flipped and is a power of ten off as well.
• (2) One power of ten too many - the slip of writing 1/(1.6) as 6.25 instead of 0.625. Correctly, 1/(1.6×10⁻¹⁹)=0.625×10¹⁹=6.25×10¹⁸.
• (3) Right digits and size of exponent, wrong sign: n=1/(1.6×10⁻¹⁹) is a huge number, 10⁺¹⁸, not 10⁻¹⁸.

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