Physics Circle home Student Login

Home›Chapters›Moving Charges and Magnetism PYQs›Force on Current-Carrying Conductors›Question 24

NEET 2023 · Force on Current-Carrying Conductors

Force on Current-Carrying Conductors question from NEET 2023

Q24NEET 2023Easy

Force on Current-Carrying Conductors

A wire carrying a current II along the positive xx-axis has length LL. It is kept in a magnetic field B⃗=(2i^+3j^−4k^) T\vec{B} = (2\hat{i} + 3\hat{j} - 4\hat{k})\text{ T}. The magnitude of the magnetic force acting on the wire is:

Show answer and solution

Answer: (b)

  1. F⃗=IL⃗×B⃗\vec{F} = I\vec{L} \times \vec{B} with L⃗=Li^\vec{L} = L\hat{i}; the i^\hat{i} part of B⃗\vec{B} gives no force.
  2. i^×(2i^+3j^−4k^)=3k^+4j^\hat{i} \times (2\hat{i} + 3\hat{j} - 4\hat{k}) = 3\hat{k} + 4\hat{j}
  3. ∣F⃗∣=IL32+42=5 IL|\vec{F}| = IL\sqrt{3^2 + 4^2} = 5\,IL
  4. So the answer is (b).
Report a mistake

More questions on Force on Current-Carrying Conductors