A current of 22.7 A flows through an electric heater operating on 120 V.  What is the heater's resistance?

Lightbulb A is marked 25.0 W 120. V, and lightbulb B is marked 100. W 120. V. These labels mean that each lightbulb has its respective power delivered to it when it is connected to a constant 120.-V source. (a) Find the resistance of each lightbulb. (b) During what time interval does 1.00 C pass into lightbulb A? (c) Is this charge different upon its exit versus its entry into the lightbulb? Explain. (d) In what time interval does 1.00 J pass into lightbulb A? (e) By what mechanisms does this energy enter and exit the lightbulb? Explain. (f) Find the cost of running lightbulb A continuously for 30.0 days, assuming the electric company sells its product at 0.110 per kWh.

When resistors with different resistances are connected in parallel, which of the following must be the same for each resistor? Choose all correct answers, (a) potential difference (b) current (c) power delivered (d) charge entering each resistor in a given time interval (e) none of those answers

A car battery with a 12-V emf and an internal resistance of 0.050 is being charged with a current of 60 A. Note that in this process the battery is being charged. (a) What is the potential difference across its terminals? (b) At what rate is thermal energy being dissipated in the battery? (c) At what rate is electric energy being converted to chemical energy? (d) What are the answers to (a) and (b) when the battery is used to supply 60 A to the starter motor?