A potential difference of 30 V is applied between the ends of a conductor of length 100 m and resistance 0.5 Ω and uniform area of cross-section. The total linear momentum of free electrons is:
Correct answer: C. 3.4 x 10^-8 kg/s
- A. 3.4 x 10^-6 kg/s
- B. 4.3 x 10^-6 kg/s
- C. 3.4 x 10^-8 kg/s
- D. 4.3 x 10^-8 kg/s
Explanation
The correct answer is 3.4 × 10-8 kg/s. To find the total linear momentum of free electrons, first calculate the current using Ohm's Law: I = V/R, where V is the potential difference and R is the resistance. Then, find the drift velocity using the formula vd = I / (nAe), where n is the electron density, A is the area of cross-section, and e is the elementary charge. Using the correct values will lead to the accurate computation of momentum. The incorrect options arise from errors in calculating these intermediate steps, leading to incorrect drift velocities and thus incorrect momentum values.
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