A battery with EMF 90.0 V has internal resistance Rb = 8.48 Ω.
What is the reading Vv of a voltmeter having total resistance Rv = 475 Ω when it is placed across the terminals of the battery?
What is the maximum value that the ratio Rb / Rv may have if the percent error in the reading of the EMF of a battery is not to exceed 2.50%?
On average, an electric water heater operates for 1.8 h each day.
If the cost of electricity is $0.34 kWh, what is the cost of operating the heater during a 30-day month?
What is the resistance of a typical water heater?
Part A = yes
Part B = The graph is a straight line where V = R * I. R is the slope and is linear. This is the definition of an ohmic resistor (Ohm’s law is V = IR).
Part C = 2.0 Ω
Part D = 18 V
The figure shows data on the dependence of the current through a resistor on the voltage across that resistor.
Is the resistor ohmic?
Explain your reasoning.
What is the value of its resistance?
Use the data to predict what voltage would be needed to produce a 9.0 A current in the resistor.
A 1500-W heater is designed to be plugged into a 120-V outlet.
What current will flow through the heating coil when the heater is plugged in?
What is R, the resistance of the heater?
How long does it take to raise the temperature of the air in a good-sized living room (3.00m x 5.00m x 8.00m) by 10.0°C?
In the circuit in the figure, a 20-ohm resistor sits inside 103 g of pure water that is surrounded by insulating Styrofoam.
If the water is initially at temperature 11.7 °C, how long will it take for its temperature to rise to 57.3 °C?16