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Physics · PYQ NEET UG 2021
हिन्दीAn infinitely long straight conductor carries a current of \( 5\text{ A} \) as shown. An electron is moving with a speed of \( 10^5\text{ m/s} \) parallel to the conductor. The perpendicular distance between the electron and the conductor is \( 20\text{ cm} \) at an instant. Calculate the magnitude of the force experienced by the electron at that instant.
Correct answer · Option 3
\( 8 \times 10^{-20}\text{ N} \)
Explanation
Magnetic field \( B = \frac{\mu_0 I}{2\pi r} = \frac{4\pi \times 10^{-7} \times 5}{2\pi \times 0.2} = 5 \times 10^{-6}\text{ T} \). Force \( F = qvB = (1.6 \times 10^{-19}) \times 10^5 \times (5 \times 10^{-6}) = 8 \times 10^{-20}\text{ N} \).
