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Home Physics Class 12 Physics To draw the I – V characteristics curve of p-n junction in forward bias & reverse bias
Class 12 Physics Lab Experiments

To draw the I – V characteristics curve of p-n junction in forward bias & reverse bias



Aim

To draw the I – V characteristics curve of p-n junction in forward bias & reverse bias.

Apparatus

A p-n junction semi-conductor diode, a three volt battery, a high resistance, a rheostat, a voltmeter (0- 3v), a milli ammeter (0-.30 mA), one – way key, connecting wires.

Circuit Diagram

Observations:

Least count of voltmeter = 0.02 & 1 v/div Zero error = –

Least count of milli-ammeter = 0.2 mA/div Zero error = –

Least count of micro-ammeter = 2μ A/div Zero error = –

Observations Table :

S.No. Forward Bias Voltage (V) Forward Current (mA) Reverse bias Voltage (V) Reverse Current ( μA)
1 10 x 0.02 = 0.20 2 x 0.2 = 0.4 10 x 1 = 10 5 x 2 = 10
2 0.30 4 x 0.2 = 0.8 15 16
3 0.40 6 x 0.2 = 1.6 20 22
4 0.50 11 x 0.2 = 2.2 25 30
5 0.60 18 x 0.2 = 3.6 30 38
6 0.70 23 x 0.2 = 4.6 35 48
7 0.80 31 x 0.2 = 6.2 40 60
8 0.90 39 x 0.2 = 7.8 45 72

IV Curve for PN Junction Diode

Calculations:

Graph is plotted between forward – bias voltage (V F) (on x-axis) and forward current, I F (on y – axis)

Scale: X – axis: 1 cm = V of V F Y – axis: 1 cm = mA of I F

Graph is plotted between reverse bias voltage, VR(along X’ axis) and reverse current, I R(along Y’ axis).

Scale: X’ axis = 1 cm = V of VR Y’ axis = 1 cm = μA of IF

Result:

The obtained curves are the characteristics curves of the semi-conductor diode.

Precautions:

  1. All connections should be neat, clean & tight.
  2. Key should be used in circuit & opened when the circuit is not being used.
  3. Forward bias voltage beyond breakdown should not be applied.

Sources of error:

The junction diode supplied maybe faulty.