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PHY 102 Test Compilation PHY 102 17 Objective Question

Question

In a parallel-plate capacitor, the distance d between the plates is 3cm, the area of each plate is 15cm2, and the voltage across them is 5V. Calculate the capacitance. Take permittivity of free space to be ε0 = 8.854 × 10-12 C2/Nm2.
Options
A 3.33 &times; 10<sup>-13</sup> F
B 9.31 &times; 10<sup>-11</sup> F
C 4.43 &times; 10<sup>-13</sup> F
Correct Answer
D 1.29 &times; 10<sup>-12</sup> F
Correct Answer

Option C is the correct answer.

Detailed Explanation

The capacitance (C) of a parallel-plate capacitor is given by the formula:C = ε0 * A / dWhere: ε0 = 8.854 × 10-12 C2/Nm2 (permittivity of free space)A = 15 cm2 = 15 × (10-2 m)2 = 15 × 10-4 m2d = 3 cm = 3 × 10-2 mC = (8.854 × 10-12 C2/Nm2) * (15 × 10-4 m2) / (3 × 10-2 m)C = (8.854 × 10-12 * 15 / 3) × 10-4 / 10-2 FC = (8.854 × 10-12 * 5) × 10-2 FC = 44.27 × 10-14 FC = 4.427 × 10-13 FThe closest option is 4.43 × 10-13 F.

Hint

Convert all units to SI (meters) before applying the formula C = ε0A/d.

Question Info