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PhysicsNEET 2021Force on a moving charge and on a current

Moving Charges and Magnetism

In the product

F⃗=q(v⃗×B⃗)=qv⃗×(Bi^+Bj^+B0k^)\vec F = q(\vec v \times \vec B) = q\vec v \times \left(B\hat i + B\hat j + B_0\hat k\right)

for q=1q = 1 and v⃗=2i^+4j^+6k^\vec v = 2\hat i + 4\hat j + 6\hat k and F⃗=4i^−20j^+12k^\vec F = 4\hat i - 20\hat j + 12\hat k, what will be the complete expression for B⃗\vec B?

  1. A.−8i^−8j^−6k^-8\hat i - 8\hat j - 6\hat k
  2. B.−6i^−6j^−8k^-6\hat i - 6\hat j - 8\hat k✓
  3. C.8i^+8j^−6k^8\hat i + 8\hat j - 6\hat k
  4. D.6i^+6j^−8k^6\hat i + 6\hat j - 8\hat k

You have the answer. The worked solution — and why the other three were written — is part of a paid pack.

More from this chapter in past papers

From Physics › Moving Charges and Magnetism › Force on a moving charge and on a current — lectures, notes and every past question on it.

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