Magnetic field along the axis of the coil

a) Circular coil apparatus

Coil on board arrangement
Coil turns: 140
Material: 99% Pure copper
Slider: 50 cm
Compass: 4 inch with mirror under needle to reduce error
Coil diameter: 180 mm
Commutator: 4 key type

b) Regulated battery eliminator

Output: Regulated DC output
Voltage: Selectable (1.2, 2, 4, 6, 8, 10, 12V)
Max current: 2 A
Key: Built in switch

c) Digital ammeter

Range: 0-2 A
Resolution: 0.01 A
Rated Input: 220 V/50 Hz or 110 V/60 Hz
Power consumption: <20 W
Cabinet: Acrylic body, aluminium bottom

d) Rheostat and connecting wire

Tube Length: 300 mm
Contact: Spring loaded Copper blades
Resistance wire: Nichrome
Terminals: 3 ( X-0-Y )
Max. current: 2 A
Max. resistance: 100 Ω