BITSAT2021PhysicsMagnetic Effects of CurrentActual
A solenoid is 2 ~m long and 3 ~cm in diameter. It has 5 layers of winding of 1000 turns each and carries a current of 5 ~A . What is the magnetic field at its centre ? Use the standard value of ₀ .
Options
- A1.57 10⁻⁴ ~T
- B2.57 10⁻³ ~T
- C1.57 10⁻² ~T
- D3.57 10⁻⁶ ~T
Correct answer
C. 1.57 10⁻² ~T
Step-by-step solution
Length of solenoid, l=2 ~m Total number of turns, N =5 1000=5000 Number of turns per unit length, n = N l = 5000 2 =2500 ~m ⁻¹ Current, I = 5A Now, B = ₀ nI =4 10⁻⁷ 2500 5 ~T =1.57 10⁻² ~T