Answer the following questions related to electric current in a metallic conductor.
PHYSICS · Multi-part · CBSE · Physics · Current Electricity · Current Electricity
Problem
Answer the following questions related to electric current in a metallic conductor.
(i) Define electric current and state its SI unit.
(ii) Show that the average electric current Iav flowing through a conductor in a time interval Δt is given by Iav=ΔtΔQ, where ΔQ is the charge crossing any cross-section of the conductor in that interval.
(iii) Explain how the sign of electric current is decided when the moving charges are electrons. Illustrate your answer with an example in which a charge of −4C crosses a cross-section in 2s. State the value and sign of the current in this case.