Assessment: Electrical Energy, Power and Heating Effect of Electric Current

A battery has EMF 6 V and internal resistance 0.4 Ω. Find its terminal voltage when it drives 1.5 A.

A device operates at 9 V, drawing 2 A. Find its power.

A current of 5 A flows through a 2 Ω resistor for 20 seconds. Find the heat generated.

A heater delivers 800 W at 200 V. Find the resistance of its heating element.

Four identical 2 V cells, each with internal resistance 0.1 Ω, are connected in series. Find the total internal resistance.

A battery's terminal voltage reads 11.4 V while supplying 3 A, with an EMF of 12 V. Find its internal resistance.

A fuse wire is designed to melt (breaking the circuit) when current exceeds a safe limit. Which physics principle explains this?

A power bank contains multiple lithium cells wired in parallel rather than series. What is the main benefit?

An appliance rated at 2000 W runs for 3 hours. Find the energy used, in kWh.

Two identical heating elements, each 40 Ω, are connected in parallel and operated at 200 V. Find the total power dissipated.