Physics Ch. 26

The potential difference between the terminals of a battery, when current flows to an external circuit, is referred to as the

terminal voltage

In Fig. 26-5 shown below, the resistors A, B and C have resistances R, 2R, and R respectively. Which resistor dissipates the most power?

C

Decreasing the resistance of an ammeter's shunt resistance

allows it to measure a larger current at full scale deflection.

When resistors are connected in series

the current flowing in each is the same

A current reading is obtained by properly placing an ammeter in a circuit consisting of one resistor and one battery. As a result,

the current flowing in the circuit decreases

Kirchhoff's junction rule is a statement of

the law of conservation of charge.

Kirchhoff's loop rule is a statement of

the law of conservation of energy

When resistors are connected in parallel, we can be certain that

the potential difference across each is the same.

If you connect two identical storage batteries together in parallel, and place them in a circuit, the combination will provide

the same voltage and twice the total charge that one battery would

Three identical resistors are connected in series to a 12-V battery. What is the voltage across any one of the resistors?

4 V

Three identical resistors are connected in parallel to a battery. If the current of 12 A flows from the battery, how much current flows through any one of the resistors?

4 A

Which of the following equations represents a Kirchhoff's voltage rule for the circuit shown in Fig. 26-9?

+6 V - (12Ω) i1 - (8Ω) i2 + 4 V = 0 V

Which of the equations here is valid for the circuit shown in Fig. 26-10?

-2 - I1 - 2I2 = 0

An ideal ammeter is one that does not change the behavior of a circuit when it is properly used to measure current. The internal resistance of such a meter is

0 Ω

Three identical resistors are connected in series to a battery. If the current of 12 A flows from the battery, how much current flows through any one of the resistors?

12 A

Three identical resistors are connected in parallel to a 12-V battery. What is the voltage of any one of the resistors?

12 V

In Fig. 26-2 all the lightbulbs are identical. The lightbulbs are ranked in decreasing order of their brightness. What is the correct ranking?

A, (B and C are the same.)

State Kirchhoff's junction rule.

At any junction point, the sum of all the currents entering the junction must equal the sum of all the currents leaving the junction.

In Fig. 26-6 shown below what combination of values for the emfs of the batteries would make the electric current in the circuit equal to zero?

E1 = E2 and E3 = 2E1

For the circuit shown in Fig. 26-8, which equation is correct for loop2 (going clockwise)?

E2 + R3I3 - E3 + R2I2 = 0

Fig. 26-7 shows a junction with currents labeled I1 to I6. Which of the following statements is correct?

I1 + I2 = I6 + I4

An RC circuit is connected across a DC voltage source through an open switch. The switch is closed at t = 0 s. Which of the following is a correct statement regarding the circuit?

Once the capacitor is fully charged, there is no current in the circuit

In Fig. 26-3 which resistor has the largest value of the electric current?

R3

You obtain a 100-W light bulb and a 50-W light bulb. Instead of connecting them in the normal way, you devise a circuit that places them in series across normal household voltage. Which statement is correct?

The 50-W bulb glows more brightly than the 100-W bulb

Fig. 26-1 shows three identical lightbulbs connected to a battery. What happens to the brightness of lightbulb 1 when the switch S is closed?

The brightness increases

The lamps in a string of Christmas tree lights are connected in parallel. What happens if one lamp burns out? (Assume negligible resistance in the wires leading to the lamps.)

The brightness of the lamps will not change appreciably.

An RC circuit is connected across a DC voltage source through an open switch. The switch is closed at t = 0 s. Which of the following is a correct statement regarding this circuit? (capacitor)

The charge on the capacitor after four time constants is about 98% of the maximum value

A voltage reading is obtained by placing a voltmeter across a resistor. What happens to the total current flowing in the circuit as a result of this action?

The current increases.

State Kirchhoff's loop rule.

The sum of the changes in potential around any closed path of a circuit must be zero.

Which one of the following is a correct statement for a number of resistors connected in series or parallel?

The total resistance in a parallel circuit decreases as more resistors are added

Four unequal resistors are connected in a parallel circuit. Which one of the following statements is correct about this circuit?

The total resistance is less than the smallest resistor.

Four unequal resistors are connected in a series circuit. Which one of the following statements is correct about this circuit?

The total resistance is more than the largest resistor

Which of the following combinations would make a good analog ammeter?

a coil with a small resistance in series

In Fig. 26-4 four identical resistors labeled A to D are connected to a battery as shown. S1 and S2 are switches. Which of the following actions would result in the greatest increase in the current through resistor A?

closing both switches

The potential difference between the terminals of a battery, when no current flows to an external circuit, is referred to as the

emf

A resistor and a capacitor are connected in series to an ideal battery of constant terminal voltage. At the moment contact is made with the battery, the voltage across the resistor is

equal to the battery's terminal voltage

An ideal voltmeter is one that does not change the behavior of a circuit when it is properly used to measure potential difference. The internal resistance of such a meter is

infinite

An unknown resistor is wired in series with an ammeter, and a voltmeter is placed in parallel across both the resistor and the ammeter. This network is then placed across a battery. If one computes the value of the resistance by dividing the voltmeter reading by the ammeter reading, the value obtained

is greater than the true resistance.

An unknown resistor is wired in series with an ammeter, and a voltmeter is placed in parallel across the resistor only. This network is then connected to a battery. If one computes the value of the resistance by dividing the voltmeter reading by the ammeter reading, the value obtained

is less than the true resistance

As more resistors are added in series to a constant voltage source, the power supplied by the source

power supplied decreases.

As more resistors are added in parallel to a constant voltage source, the power supplied by the source

power supplied increases

A galvanometer can be converted to an ammeter by the addition of a

small resistance in parallel

When two or more resistors are connected in series to a battery

the total voltage across the combination is the algebraic sum of the voltages across the individual resistors, the same current flows through each resistor, and the equivalent resistance of the combination is equal to the sum of the resistances of each resistor

When two or more resistors are connected in parallel to a battery

the voltage across each resistor is the same, the total current flowing from the battery equals the sum of the currents flowing through each resistor, and the equivalent resistance of the combination is less than the resistance of any one of the resistors.

If you connect two identical storage batteries together in series ("+" to "-" to "+" to "-"), and place them in a circuit, the combination will provide

twice the voltage, and the same current will flow through each.

In order to construct a voltmeter from a galvanometer, one normally would

use a very large series resistor.

A resistor and a capacitor are connected in series to an ideal battery of constant terminal voltage. At the moment contact is made with the battery, the voltage across the capacitor is

zero

A resistor and a capacitor are connected in series to an ideal battery of constant terminal voltage. When this system reaches its steady-state, the voltage across the resistor is

zero

If you connect two identical storage batteries together in series ("+" to "-" to "-" to "+"), and place them in a circuit, the combination will provide

zero volts.