(a) Resistance Specific resistance; Calculation of total resistance using series, parallel and series–parallel combinations; Operation and use of potentiometers and rheostats; Operation of Wheatstone Bridge.

(b) Resistor Positive and negative temperature coefficient conductance; Resistor colour code, values and tolerances, preferred values, wattage ratings; Resistors in series and in parallel; Fixed resistors, stability, tolerance and limitations, methods of construction; Variable resistors, thermistors, voltage-dependent resistors; Construction of potentiometers and rheostats; Construction of Wheatstone Bridge.