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COMEDK · Physics · 21. Magnetic Effects of Current

A long solenoid X having 400 turns per cm carries a current I . The magnetic field produced at its centre by this solenoid is \(3.14 \times 10^{-2} T\). The magnetic field produced by another solenoid \(Y\) at its centre having 300 turns per cm carries a current \(\dfrac{\mathrm{I}}{3}\). The magnetic field produced by Y at its centre is:

  1. A \(12.56 \times 10^{-2} T\)
  2. B \(0.785 \times 10^{-2} T\)
  3. C \(1.256 \times 10^{-2} T\)
  4. D \(2.785 \times 10^{-2} T\)
Verified Solution

Answer & Solution

Correct Answer

(B) \(0.785 \times 10^{-2} T\)

Step-by-step Solution

Detailed explanation

The magnetic field \(B\) at the centre of a long solenoid is given by the formula \(B = \mu_{0} n I\), where \(n\) is the number of turns per unit length and \(I\) is the current. For solenoid X, we have \(n_{X} = 400 \text{ turns/cm} = 40000 \text{ turns/m}\) and…