Higher Physics Lab Electricity & Magnetism



Exp-1 To measure the force between current carrying conductor and determine the permeability of air.
Exp-2 To measure the force of attraction between charged capacitor plates and determine the permittivity of air.
Exp-3 To verify the relationship of speed of light with permeability and permittivity of air.

  • High current power supply.
  • High voltage DC power supply.
  • Very sensitive coulomb and current balance.
  • Diode laser based optical lever.
  • Permittivity of air.
  • Null Method
  • Electrostatic force.
  • current balance
  • Coulomb law.
  • Parallel plate
  • Conductor.

Principle and Working:
Repulsive forces between two current carrying conductors, which is very small, is measured using a very sensitive balance technique based on a diode laser, scale and fractional weights to form an optical lever. This measurement is used to calculate permeability of air. Similarly small attractive forces between two charged capacitor plates is measured. This measurement is used to calculate the permittivity of air.
An indirect estimate of the speed of light can be made from the experimental values of permeability and permittivity which verifies the relationship.


Cat. No. Item Name Qty.
SV244 Coulomb and current balance kit 1
SE1003 Power supply 0-30V DC, 0-20A 1
SEB02 Power supply 0-600V, 10mA 1
SG204 Weight box 1
SG110 Cylindrical base 2
CH829 Diode laser with adapter 1
SP134 Wooden scale 1
LP18 Connecting lead 2
C4178 Resistance module 1

Electricity & Magnetism Experiments