Question
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 .
BITSAT
Physics
Magnetic Effects of Current
2021
BITSAT 2021
BITSAT Physics Question (2021) — Solution
Options
- A. 1.57 10^ -4 ~T
- B. 2.57 10^ -3 ~T
- C. 1.57 10^ -2 ~T
- D. 3.57 10^ -6 ~T
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
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