AP EAMCET2001PhysicsMagnetic Properties of Matter
A magnet freely suspended in a vibration magnetometer makes 40 oscillations per minute at place A and 20 oscillations per minute at a place B . If the horizontal component of earth's magnetic field at A is 36 10⁻⁶ ~T , then its value at B is
Options
- A30 10⁻⁶ ~T
- B9 10⁻⁶ ~T
- C144 10⁻⁶ ~T
- D288 10⁻⁶ ~T
Correct answer
B. 9 10⁻⁶ ~T
Step-by-step solution
Time period of magnet, T=2 I M H In both the condition magnet is same. So, aligned T & 1 H T_A T_s & = H_n H_A aligned gathered 60 / 40 60 / 20 = H_n 36 10⁻⁴ 1 2 = H_n 36 10⁻⁶ gathered Squaring both sides 1 4 = H_n 36 10⁻⁶ H_n=9 10⁻⁴ ~T