NEET2024PhysicsMagnetic Effects of CurrentActual
In a uniform magnetic field of 0.049 T , a magnetic needle performs 20 complete oscillations in 5 seconds as shown. The moment of inertia of the needle is 9.8 10⁻⁶ ~kg ~m ^2 . If the magnitude of magnetic moment of the needle is x 10⁻⁵ Am ^2 , then the value of ' x ' is :
Options
- A128 ^2
- B50 ^2
- C1280 ^2
- D5 ^2
Correct answer
C. 1280 ^2
Step-by-step solution
Time period of Oscillation, T=2 I M B aligned & 1 4 =2 9.8 10⁻⁶ M 0.049 & 1 16 =4 ^2 9.8 10⁻⁶ M 49 10⁻³ & M= 4 ^2 9.8 10⁻⁶ 49 10⁻³ 16 & = 4 ^2 9.8 16 10⁻³ 49 & =12.8 ^2 10⁻³ 10⁻² 10^2 & =1280 ^2 10⁻⁵ Am ^2 & aligned