Magnetic Needle Oscillation
Example 5.1: Oscillating Magnetic Needle
This simulation demonstrates how to calculate magnetic field strength from the oscillation period of a magnetic needle.
Magnetic moment (m):
6.7 × 10⁻² Am²
Moment of inertia (I):
7.5 × 10⁻⁶ kg m²
Oscillations:
10 in 6.70 s
Time period (T):
0.67 s
Magnetic field (B):
0.01 T
Key Formula
T = 2π√(I/mB)
B = 4π²I/(mT²)
Calculations
T = 6.70 s / 10 oscillations = 0.67 s
B = 4 × (3.14)² × 7.5 × 10⁻⁶ / (6.7 × 10⁻² × (0.67)²)
B = 0.01 T
