The heating element of a coffeemaker operates at 120 V and carries a current of 2.50 A. Assuming the water absorbs all of the energy converted by the resistor, calculate how long it takes to heat 0.515 kg of water from room temperature (23.0°C) to the boiling point. _______min

The total energy used by an electric iron operating on 42 V for 200 seconds on a current of 4.8 A is  ____________

Consider the following circuit diagram. The potential difference across the battery is 40.0 volts, and it supplies a current of 5.00 amperes to the circuit. There is a current of of 2.70 amperes flowing through R1. Resistor R2 has a resistance of 5.50 ohms. What is the resistance of R3? Answer in ohms to two decimal places, but do not include units in your answer.

If the battery in the circuit below is 7.16V, resistor R1=331.15ΩΩ, and resistor R2=51.49ΩΩ, what is the magnitude of the current flowing through the circuit?  Please give your answer in units of milli-Amps (mA).

What current flows through a 2.74 cm diameter rod of pure silicon that is 25.0 cm long, when 1000 V is applied to it? (Such a rod may be used to make nuclear particle detectors, for example.) The resistivity of pure silicon is 2.30  103 Ω · m. _____A

When initially at 20°C, the power being supplied to a 691 Ohm resistor in a circuit is 8.29 W. Over time, the temperature of the resistor increase to 168°C. If the temperature coefficient of resistivity of the material composing the resistor is 5.75 x 10-3 °C-1, what power is supplied to the resistor at its operating temperature?

When a car's starter is in use, it draws a large current. The car's lights draw much less current. As a certain car is starting, the current through the battery is 64.8 A and the potential difference across the battery terminals is 8.82 V. When only the car's lights are used, the current through the battery is 2.18 A and the terminal potential difference is 10.7 V.   Find the battery's emf. ______ Find the internal resistance. ______