Question

Pranav once had put his finger inside the electrical socket and had gotten a bad electric shock. When he learned about random motion of electrons and then the drift speed when there is a current, he concluded that drift speed must be very high compared to the speed of random motion and that is why you get electric shocks when there is a current. Is he right?

• A. The drift speed of electrons is usually very high compared to the order of speed of random motion due to temperature.
• B. The drift speed is comparable to the order of speed of random motion due to temperature.
• C. The drift speed is slightly lesser (maybe a few times lesser) than the order of speed of random motion due to temperature.
• D. The drift speed is very very less compared to the order of speed of random motion due to temperature.

Answer 1

The correct option is D The drift speed is very very less compared to the order of speed of random motion due to temperature.

The drift speed is generally of the order of ${10}^{-4}m/s$ and the random motion speed is of ${10}^{5}m/s$. The drift speed is way too smaller than the random speed. The reason Pranav never feels current in an isolated conductor, although the electrons are moving with such high speeds is becuse there is no net motion of electrons across any cross-section. For any given time, no. of electrons moving to one side is equal to those moving to the other side. The reason why Pranav got such a shock is not because of the mechanical force of the electrons but because of something else, current going through his body to the earth!!
HOW?
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