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Questions on Characteristic Curves - Filament Lamp

Q2.

A filament lamp rated 12 V, 1.0 A has a resistance of 4.0 when it carries no current.

(a) On the axes below, sketch the form of the current against voltage characteristic for this lamp.

    • corrct shape in one quadrant
    • symmetrical trace in other
    • Plotted point (1.0, 1.2)
    • Plotted point (0, 0)
    • Gradient at origin of 4.0

(4)

(b) The filament lamp is one example of a non-ohmic device.

(i) State what is meant by the term non-ohmic.

In a non-ohmic component V is not directly proportional to I - in other words the resistance is not constant - it varies with potential difference applied.

(1)

(ii) Name one other example of a non-ohmic device.

semiconductor diode

(1)
(Total 6 marks)