Physics

Problem

Device Z is tested at constant temperature and the following readings are recorded:

(V\,\text{in V},\; I\,\text{in A})

→

(1,0.25),\; (2,0.40),\; (3,0.45)

. Which inference about the behaviour of Z is correct? a)

\text{Z is non-ohmic; its resistance decreases as current increases}

\text{Z is non-ohmic; its resistance increases as current increases}

\text{Z exhibits a negative temperature coefficient of resistance because its current rises with heating}

\text{Z obeys Ohm’s law since the V–I points lie on a straight line through the origin}