Question 1

When a 29-Ω resistor is connected across a 16-V battery,a current of 470 mA flows.What is the resulting terminal voltage of the battery?
A) 34 V
B) 7.5 V
C) 13.6 V
D) ​61.7 V
E) ​0.6 V

Accepted Answer

We can use Ohm's law to find the internal resistance of the battery.
V = IR
16 V = (0.47 A)(R)
R = 34.04 Ω
Then we can use the formula for voltage division to find the terminal voltage of the battery.
V = E x (R/(R+29))
V = 16 x (34.04/(34.04+29))
V = 13.55 V
Therefore, the resulting terminal voltage of the battery is approximately 13.6 V (Option C).

Question 2

Three resistors,each with resistance R₁,are in series in a circuit.They are replaced by one equivalent resistor,R.Comparing this resistor to the first resistor of the initial circuit,which of the following is true? A) The current through R equals the current through R₁. B) The voltage across R equals the voltage across R₁. C) The power given off by R equals the power given off by R₁. D) R is less than R₁.

Accepted Answer

When resistors are in series, the same current flows through each resistor. Therefore, the current through the equivalent resistor R is the same as the current through each of the original resistors, R₁.

Question 3

When a 21-Ω resistor is connected across a 14-V battery,a current of 458 mA flows.What is the internal resistance of the battery?
A) 212 Ω
B) 9.6 Ω
C) 30.6 Ω
D) 0.7 Ω
E) ​1.1 Ω

Accepted Answer

Internal resistance = (Battery voltage - Terminal voltage) / Current = (14 V - 12 V) / 0.458 A = 9.6 Ω

Question 4

Three resistors connected in series have individual voltages labeled ΔV₁,ΔV₂ and ΔV₃,respectively.Which of the following expresses the value of the total voltage ΔV_T taken over the three resistors together? A) ΔV_T = ΔV₁ + ΔV₂ + ΔV₃ B) ΔV_T = (1/ΔV₁ + 1/ΔV₂ + 1/ΔV₃) C) ΔV_T = ΔV₁ = ΔV₂ = ΔV₃ D) ΔV_T = (1/ΔV₁ + 1/ΔV₂ + 1/ΔV₃)−¹

Accepted Answer

When resistors are connected in series, the total voltage applied across the resistors is equal to the sum of the individual voltages across each resistor. Therefore, the correct expression for the total voltage applied across the three resistors is: ΔV_T = ΔV₁ + ΔV₂ + ΔV₃ Option B represents the expression for the equivalent resistance of three resistors connected in parallel, not in series. Option C represents the case when all three resistors have the same value, which is not given in the problem statement. Option D is incorrect because it includes a term (¹) that is not defined in the problem statement.

Question 5

Three resistors connected in series each carry currents labeled I₁,I₂ and I₃.Which of the following expresses the value of the total current I_T in the system made up of the three resistors in series? A) I_T = I₁ + I₂ + I₃ B) I_T = (1/I₁ + 1/I₂ + 1/I₃) C) I_T = I₁ = I₂ = I₃ D) I_T = (1/I₁ + 1/I₂ + 1/I₃)−¹

Accepted Answer

In a series circuit, the current flowing through each resistor is the same. Therefore, the total current $I_{T}$ is equal to the current through each resistor ($I_{1} = I_{2} = I_{3}$).

Question 6

Which voltage is not caused by a source of emf?
A) the voltage across a charged capacitor
B) the voltage across two copper-iron junctions at different temperatures
C) the voltage across the terminals of a dry cell battery
D) the voltage from an electric generator

Accepted Answer

The voltage across a charged capacitor is not caused by a source of emf. It is the result of the accumulation of charge on the plates of the capacitor, which creates an electric field between them. The other choices, B, C, and D, are all examples of voltages that are caused by sources of emf.

Question 7

Three 5-Ω resistors are connected in parallel.What is their equivalent resistance?
A) 0.12 Ω
B) 2.5 Ω
C) 0.6 Ω
D) 1.7 Ω
E) ​5 Ω

Accepted Answer

The answer of Three 5-Ω resistors are connected in parallel.What...

Question 8

When a 19-Ω resistor is connected across a 5-V battery,a current of 489 mA flows.What is the power output delivered by the emf of the battery?
A) 95 W
B) 79.5 W
C) 4.5 W
D) 1.2 W
E) ​46.5 W

Accepted Answer

The power output delivered by the emf of the battery can be found using the formula P = IV, where P is power, I is current, and V is voltage. Here, I = 489 mA = 0.489 A, and V = 5 V. Using Ohm's law, we can find the resistance R = V/I = 5/0.489 = 10.211 Ω. However, the question tells us that a 19-Ω resistor is connected across the battery, so the effective resistance in the circuit is R = 19 Ω. Using the formula P = IV again, we get P = (0.489 A)^2 x 19 Ω = 4.472 W ≈ 4.5 W, which is choice C.

Question 9

Which resistor is in series with resistor R? A) R₁ B) R₂ C) R₃ D) R₄

Accepted Answer

The answer of Which resistor is in series with resistor...

Question 10

The two ends of a 2.3-Ω resistor are connected to a 9.9-V battery.What is the total power delivered by the battery to the circuit?
A) 1.9 W
B) 42.6 W
C) 4.3 W
D) 52.4 W
E) ​225.4 W

Accepted Answer

Power = (Voltage)^2 / Resistance = (9.9 V)^2 / 2.3 Ω = 42.6 W

Question 11

Four 7-Ω resistors are connected in series.What is their equivalent resistance?
A) 28 Ω
B) 7 Ω
C) 21 Ω
D) 1.8 Ω
E) ​11 Ω

Accepted Answer

When resistors are connected in series, their resistances add up. Therefore, 7 Ω + 7 Ω + 7 Ω + 7 Ω = 28 Ω.

Question 12

Resistors of values 5 Ω,17 Ω,and 24 Ω are connected in series across a battery with a small internal resistance.Which resistor dissipates the greatest power?
A) the 5-Ω resistor
B) the 17-Ω resistor
C) the 24-Ω resistor
D) The answer depends on the internal resistance of the battery.

Accepted Answer

In a series circuit, the resistor with the highest value will dissipate the most power. The power dissipated in a resistor is given by P = (V^2)/R, where V is the voltage across the resistor and R is its resistance. Since the voltage across each resistor in a series circuit is the same, the resistor with the highest resistance will dissipate the most power. Therefore, the 24-Ω resistor will dissipate the greatest power in this circuit.

Question 13

The basic function of an electromotive force in a circuit is to do which of the following?
A) Convert electrical energy into some other form.
B) Convert some other form of energy into electrical.
C) Both choices (a)and (b)are valid.
D) None of the above choices are valid.

Accepted Answer

The basic function of an electromotive force is to convert some other form of energy (such as chemical, mechanical, or light) into electrical energy, which then powers the circuit. Option A is incorrect because EMF does not convert electrical energy into another form. Option C is incorrect because it only implies both choices, whereas only choice B directly addresses the function of EMF. Option D is incorrect because EMF is a valid concept in electrical engineering.

Question 14

When a light bulb is turned on,its resistance increases until it reaches operating temperature.What happens to the current in the bulb as it is warming up?
A) It stays constant.
B) It increases.
C) It decreases.
D) It increases at first and then decreases.

Accepted Answer

As the resistance of the bulb increases while warming up, according to Ohm's law (V=IR), the current flowing through the bulb would have to decrease since the voltage across the bulb remains constant. Therefore, the correct choice is C.

Question 15

Three resistors,with values of 2,7 and 8 Ω,respectively,are connected in series.What is the overall resistance of this combination?
A) 1.3 Ω
B) 5.7 Ω
C) 7 Ω
D) 17 Ω
E) ​0.8 Ω

Accepted Answer

When resistors are connected in series, the total resistance is the sum of the individual resistances: 2 Ω + 7 Ω + 8 Ω = 17 Ω.

Question 16

Three resistors with values of R₁,R₂ and R₃,respectively,are connected in series.Which of the following expresses the total resistance,R_T,of the three resistors? A) R_T = R₁ + R₂ + R₃ B) R_T = (1/R₁ + 1/R₂ + 1/R₃) C) RT = R₁ = R₂ = R₃ D) R_T = (1/R₁ + 1/R₂ + 1/R₃)−¹

Accepted Answer

Resistances in a series circuit add up, so the total resistance is the sum of the three resistors: R_T = R₁ + R₂ + R₃. Option B is the formula for the total resistance in a parallel circuit. Option C suggests all three resistors have the same resistance, which is not given in the problem. Option D includes an extra term that is not present in the formula for total resistance in a series circuit.

Question 17

Three 6-Ω resistors are connected in parallel to a 15-V battery.What is the current in any one of the resistors?
A) 21 A
B) 6.3 A
C) 2.5 A
D) 90 A
E) ​9 A

Accepted Answer

The total resistance in the circuit is:

1/R_total = 1/6 Ω + 1/6 Ω + 1/6 Ω = 3/6 Ω = 0.5 Ω

Using Ohm's law:

V = IR
I = V/R

Thus, the current in any one of the resistors is:

I = V/R = 15 V / 6 Ω = 2.5 A

Therefore, the best choice is C.

Question 18

If R₁ < R₂ < R₃,and if these resistors are connected in series in a circuit,which one dissipates the greatest power? A) R₁ B) R₂ C) R₃ D) All are equal in power dissipation.

Accepted Answer

The power dissipated in a resistor is given by P = I^2*R, where I is the current flowing through the resistor and R is its resistance. As the resistances are connected in series, they all experience the same current. Since R₃ has the highest resistance, it will dissipate the most power according to the formula.

Question 19

The two ends of a 1.4-Ω resistor are connected to a 10.3-V battery.What is the current through the resistor?
A) 14.4 A
B) 0.1 A
C) 7.4 A
D) ​11.7 A
E) ​8.9 A

Accepted Answer

Using Ohm's Law (V = IR), the current (I) is calculated as I = V/R = 10.3V / 1.4Ω = 7.357 A, which rounds to 7.4 A.

Question 20

The internal resistances of an ideal voltmeter and an ideal ammeter are respectively (ideal meaning the behavior of the system is not changed when using the meter):
A) zero and zero.
B) infinite and infinite.
C) zero and infinite.
D) infinite and zero.

Accepted Answer

An ideal voltmeter has infinite internal resistance to ensure it does not draw any current from the circuit it is measuring, thus not affecting the circuit's operation. An ideal ammeter has zero internal resistance to ensure it does not add any resistance to the circuit it is measuring, thus not affecting the circuit's operation.

Quiz 18: Direct-Current Circuits Sources of EMF

When a 29-Ω resistor is connected across a 16-V battery,a current of 470 mA flows.What is the resulting terminal voltage of the battery?

Three resistors,each with resistance R₁,are in series in a circuit.They are replaced by one equivalent resistor,R.Comparing this resistor to the first resistor of the initial circuit,which of the following is true?

When a 21-Ω resistor is connected across a 14-V battery,a current of 458 mA flows.What is the internal resistance of the battery?

Three resistors connected in series have individual voltages labeled ΔV₁,ΔV₂ and ΔV₃,respectively.Which of the following expresses the value of the total voltage ΔV_T taken over the three resistors together?

Three resistors connected in series each carry currents labeled I₁,I₂ and I₃.Which of the following expresses the value of the total current I_T in the system made up of the three resistors in series?

Which voltage is not caused by a source of emf?

Three 5-Ω resistors are connected in parallel.What is their equivalent resistance?

When a 19-Ω resistor is connected across a 5-V battery,a current of 489 mA flows.What is the power output delivered by the emf of the battery?

Which resistor is in series with resistor R?

The two ends of a 2.3-Ω resistor are connected to a 9.9-V battery.What is the total power delivered by the battery to the circuit?

Four 7-Ω resistors are connected in series.What is their equivalent resistance?

Resistors of values 5 Ω,17 Ω,and 24 Ω are connected in series across a battery with a small internal resistance.Which resistor dissipates the greatest power?

The basic function of an electromotive force in a circuit is to do which of the following?

When a light bulb is turned on,its resistance increases until it reaches operating temperature.What happens to the current in the bulb as it is warming up?

Three resistors,with values of 2,7 and 8 Ω,respectively,are connected in series.What is the overall resistance of this combination?

Three resistors with values of R₁,R₂ and R₃,respectively,are connected in series.Which of the following expresses the total resistance,R_T,of the three resistors?

Three 6-Ω resistors are connected in parallel to a 15-V battery.What is the current in any one of the resistors?

If R₁ < R₂ < R₃,and if these resistors are connected in series in a circuit,which one dissipates the greatest power?

The two ends of a 1.4-Ω resistor are connected to a 10.3-V battery.What is the current through the resistor?

The internal resistances of an ideal voltmeter and an ideal ammeter are respectively (ideal meaning the behavior of the system is not changed when using the meter) :