Exam 20: Electric Circuits

An RC circuit consists of a resistor with resistance 1.0 k $\Omega$ , a 120-V battery, and two capacitors, C₁ and C₂, with capacitances of 20.0 µF and 60.0 µF, respectively.Initially, the capacitors are uncharged; and the switch is closed at t = 0 s. -What is the time constant of the circuit?

Five resistors are connected as shown in the diagram.The potential difference between points A and B is 25 V. -What is the current through the 3.6- $\Omega$ resistor?

Two wires, A and B, and a variable resistor, R, are connected in series to a battery.Which one of the following results will occur if the resistance of R is increased?

Four resistors and a 6-V battery are arranged as shown in the circuit diagram. -The largest potential difference is across which resistor(s)?

Which one of the following combinations of units is equivalent to the ohm?

A resistor dissipates 1.5 W when it is connected to a battery with a potential difference of 12 V.What is the resistance of the resistor?

An uncharged 5.0-µF capacitor and a resistor are connected in series to a 12-V battery and an open switch to form a simple RC circuit.The switch is closed at t = 0 s.The time constant of the circuit is 4.0 s. -Determine the value of the resistance R.

Three 15- $\Omega$ and two 25- $\Omega$ light bulbs and a 24 V battery are connected in a series circuit.What is the current that passes through each bulb?

A 3.0-A current is maintained in a simple circuit that consists of a resistor between the terminals of an ideal battery.If the battery supplies energy at a rate of 25 W, how large is the resistance?

Which one of the following statements concerning resistance is true?

The characteristics of five wires are given in the table. The gauge is a measure of the diameter of the wire; and #18 corresponds to a diameter of 1.2 × 10^-3 m; and #22 corresponds to a diameter of 6.4 × 10^-4 m.The resistivity of iron is 9.7 × 10^-8 $\Omega$ . m; and the value for copper is 1.72 × 10^-8 $\Omega$ . m. -Of the five wires, which one has the smallest resistance?

A non-ideal battery has a 6.0-V emf and an internal resistance of 0.6 $\Omega$ .Determine the terminal voltage when the current drawn from the battery is 0.5 A.

A battery is manufactured to have an emf of 24.0 V, but the terminal voltage is only 22.0 V when the battery is connected across a 10.0- $\Omega$ resistor.What is the internal resistance of the battery?

A 220- $\Omega$ resistor is connected across an ac voltage source V = (150 V) sin [2 $\pi$ (60 Hz)t].What is the average power delivered to this circuit?

Complete the following statement: The electromotive force is

Five resistors are connected as shown in the diagram.The potential difference between points A and B is 15 V. -What is the equivalent resistance between the points A and B?

Determine the power dissipated by the 40- $\Omega$ resistor in the circuit shown.

The figure shows a simple RC circuit consisting of a 10.0-µF capacitor in series with a resistor.Initially, the switch is open as suggested in the figure.The capacitor has been charged so that the potential difference between its plates is 100.0 V.At t = 0 s, the switch is closed.The capacitor discharges exponentially so that 2.0 s after the switch is closed, the potential difference between the capacitor plates is 37 V.In other words, in 2.0 s the potential difference between the capacitor plates is reduced to 37 % of its original value. -Calculate the electric potential energy stored in the capacitor before the switch is closed.

The figure shows variation of the current through the heating element with time in an iron when it is plugged into a standard 120 V, 60 Hz outlet. -What is the approximate average power dissipated in the iron?

How much energy is stored in the combination of capacitors shown?