V-I graphs show how current varies when potential difference changed. The straight line graph shows different resistors. The current through a resistor is directly proportional to P.D as long as constant temperature. Different resistors have different resistances so different slopes.
S shaped graph is filament lamp. As temperature of filament increases, resistance increases hence curve.
Third graph is diode. Current only flow through diode is one direction. Very high resistance in opposite direction.
When electrical charge flows through resistor, some electrical energy transferred to heat energy and resistor…