A student plotted potential difference against current for a small filament lamp and…
PHYSICS · Single correct · CBSE · Physics · Current Electricity · Current Electricity
Problem
A student plotted potential difference against current for a small filament lamp and obtained a curve that bends upward rather than a straight line through the origin. Which inference is most appropriate?
(a) The slope of the V–I graph gives the resistivity of the filament
(b) The resistance of the lamp decreases as current increases
(c) The lamp does not obey Ohm’s law
(d) A straight line would be obtained if current were plotted on the y-axis