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CUET · PHYSICS · PYQ PAPER 2023

A straight wire of mass 500 g and length 7 m carries a current of 1.4 A. It is suspended in mid air by a uniform horizontal magnetic field B perpendicular to the length of the wire. The magnitude of magnetic field is:

  1. A 3.5 T
  2. B 0.7 T
  3. C 0.5 T
  4. D 2.5 T
Verified Solution

Answer & Solution

Correct Answer

(C) 0.5 T

Step-by-step Solution

Detailed explanation

\( F_m = F_g \) \( I L B = mg \) \( B = \frac{mg}{IL} \) \( B = \frac{0.5 \, \text{kg} \times 9.8 \, \text{m/s}^2}{1.4 \, \text{A} \times 7 \, \text{m}} \) \( B = 0.5 \, \text{T} \)