Physics Circle home Student Login

Home›Chapters›Moving Charges and Magnetism PYQs›Moving Charge in a Magnetic Field›Question 55

JEE Main 2022 (26 Jul, Shift 1) · Moving Charge in a Magnetic Field

Moving Charge in a Magnetic Field question from JEE Main 2022 (26 Jul, Shift 1)

Q55JEE Main 2022 · 26 JUL · SHIFT 1Medium

Moving Charge in a Magnetic Field

A charge particle is moving in a uniform magnetic field (2i^+3j^) T(2\hat{i} + 3\hat{j})\text{ T}. If it has an acceleration of (αi^−4j^) m/s2(\alpha\hat{i} - 4\hat{j})\text{ m/s}^2, then the value of α\alpha will be:

Show answer and solution

Answer: (b)

  1. Magnetic force (and so acceleration) is always perpendicular to B⃗\vec B: a⃗⋅B⃗=0\vec a\cdot\vec B = 0
  2. (αi^−4j^)⋅(2i^+3j^)=2α−12=0(\alpha\hat i - 4\hat j)\cdot(2\hat i + 3\hat j) = 2\alpha - 12 = 0
  3. α=6\alpha = 6
  4. So the answer is (b) 6.
Report a mistake

More questions on Moving Charge in a Magnetic Field