27. Resistors & DC Circuits

What is current and voltage across each resistor below?

What is the voltage of the battery below?

In the circuit shown in Fig. E26.31 the batteries have negligible internal resistance and the meters are both idealized. With the switch S open, the voltmeter reads 15.0 V. What will the ammeter read when the switch is closed?

The current supplied by a battery slowly decreases as the battery runs down. Suppose that the current as a function of time is $I=\left(0.75A\right)e^{-\frac{t}{6h}}$. What is the total number of electrons transported from the positive electrode to the negative electrode by the charge escalator from the time the battery is first used until it is completely dead?

What is the value of resistor R in FIGURE EX28.16?

Two of the three resistors in FIGURE EX28.23 are unknown but equal. The total resistance between points 1 and 2 is 75Ω. What is the value of R?