A small sample tray is attached to a horizontal conductor and can move along a vertical guide. The conductor is at right angles to a uniform magnetic field.
| Quantity | Value |
|---|---|
| weight of tray and conductor | 0.024 N downwards |
| length of conductor inside the magnetic field | 6.0 cm |
| magnetic flux density | 0.20 T0.20\ \text{T}0.20 T |
| current in the conductor | 3.0 A |
| direction of the magnetic force | upwards |
Calculate the size of the unbalanced force acting on the tray and conductor.
State whether the unbalanced force acts upwards or downwards.
Use the equation
F=B×I×lF = B \times I \times lF=B×I×l