KCET2019PhysicsMagnetic Effects of Current
A magnetic needle has a magnetic moment of ( 5 10⁻² Am ² ) and moment of inertia ( 8 ) ( 10⁻⁶ kgm ² ). It hasa period of oscillation of ( 2 ~s ) in a magnetic field ( B ). The magnitude of magnetic field is approximately
Options
- A( 3.2 10⁻⁴ ~T )
- B( 1.6 10⁻⁴ ~T )
- C( 0.8 10⁻⁴ )
- D( 0.4 10⁻⁴ )
Correct answer
B. ( 1.6 10⁻⁴ ~T )
Step-by-step solution
(B) [ array l T=2 I M B 2=2 8 10⁻⁶ 5 10⁻² B Squaring 1= ² 8 10⁻⁶ 5 10⁻² B B= 3.14² 8 10⁻⁶ 5 =1.6 10⁻⁴ ~T array ]