WBJEE · Physics · Magnetic Effects of Current
A current of 1 A is flowing along positive \(x\) -axis through a straight wire of length \(0.5 \mathrm{m}\) placed in a region of a magnetic field given by \(\mathbf{B}=(2 \mathbf{i}+4 \mathbf{j}) \mathrm{T} .\) The magnitude and the direction of the force experienced by the wire respectively are
- A \(\sqrt{18} \mathrm{N},\) along positive \(z\) -axis
- B \(\sqrt{20} \mathrm{N}\), along positive \(x\) -axis
- C \(2 \mathrm{N}\), along positive \(z\) -axis
- D \(4 \mathrm{N},\) along positive \(y\) -axis
Answer & Solution
Correct Answer
(C) \(2 \mathrm{N}\), along positive \(z\) -axis
Step-by-step Solution
Detailed explanation
The force experienced by the wire placed in magnetic field, \(F=B il\) \[ \begin{array}{l} =(2 \hat{i}+4 \hat{j})\left(1 \hat{i} \times \frac{1}{2}\right) \\ =\hat{i} \times \hat{i}+4 \times \frac{1}{2}(\hat{i} \times \hat{j})=2 \hat{k} N \end{array} \] Direction of this force…
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