MHT CET20226 Aug 2022Evening ShiftPhysicsMagnetic Effects of CurrentActual
A long solenoid has 200 turns per cm and carriers a currenti. The magnetic field at its centre is 6.28 10⁻² ~Wb / m ^2 . Another long solenoid has 100 turns per cm and it carries a current i 3 . The value of magnetic field at its centre is nearly
Options
- A1.05 10⁻³ ~Wb / m ^2
- B1.05 10⁻⁴ ~Wb / m ^2
- C1.05 10⁻² ~Wb / m ^2
- D1.05 10⁻⁵ ~Wb / m ^2
Correct answer
C. 1.05 10⁻² ~Wb / m ^2
Step-by-step solution
Magnetic field due to a long solenoid is given by B= ₀ n i For solenoid with 200 turns per cm and i current flows through it, 6.28 10⁻² ~Wb / m ^2= ₀ 200 i Now, for solenoid with 100 turns per cm with current i 3 , B= ₀ 100 ( i 3 ) Introducing value of i from equation (1), B= ₀ 100 ( 1 3 6.28 10⁻² ~Wb / m ^2 ₀ 200 )=1.46 10⁻² ~Wb / m ^2B 1.05 10⁻² ~Wb / m ^2