Phys Test 2

*A 10.0-μF capacitor is charged so that the potential difference between its plates is 10.0 V. A 5.0-μF capacitor is similarly charged so that the potential difference between its plates is 5.0 V. The two charged capacitors are then connected to each other in parallel with positive plate connected to positive plate and negative plate connected to negative plate.* How much charge flows from one capacitor to the other when the capacitors are connected? (a) 17 μC (b) 33 μC (c) 67 μC (d) 83 μC (e) zero coulombs

A

A 220-Ω resistor is connected across an ac voltage source V = (150 V) sin [2π(60 Hz)t]. What is the average power delivered to this circuit? (a) 51W (b) 110 W (c) 280W (d) 320 W (e) 550W

A

A battery has a terminal voltage of 12 V when no current flows and an internal resistance of 2 Ω. The battery is placed in series with a 1-Ω resistor. Which one of the entries in the following table terminal V current thru 1-Ω (a) 4V 4A (b)4V 12A (c) 12 V 4A (d) 12 V 12A (e) 18 V 3A

A

A battery supplies a total charge of 5.0 μC to a circuit that consists of a series combination of two identical capacitors, each with capacitance C. Determine the charge on either capacitor. (a) 5.0 μC (b) 2.5 μC (c) 1.5 μC (d) 1.0 μC (e) 0.50 μC

A

A lamp uses an average power of 55 W when it is connected to an rms voltage of 120 V. Which entry in the following table is correct for this circuit? lamp resistance R (Ω) Irms (A) (a) 260 0.46 (b) 22 3.8 (c) 130 0.65 (d) 170 0.57 (e) 38 1.2

A

Complete the following statement: The electromotive force is (a) the maximum potential difference between the terminals of a battery. (b) the force that accelerates electrons through a wire when a battery is connected to it. (c) the force that accelerates protons through a wire when a battery is connected to it. (d) themaximumcapacitancebetweentheterminalsofabattery. (e) the maximum electric potential energy stored within a battery.

A

Jason's circuit has a 24-Ω resistor that is connected in series to two 12-Ω resistors that are connected in parallel. JoAnna's circuit has three identical resistors wired in parallel. If the equivalent resistance of Jason's circuit is the same as that of JoAnna's circuit, determine the value of JoAnna's resistors. (a) 90Ω (b) 48Ω (c) 30Ω (d) 24Ω (e) 12Ω

A

Two 15-Ω and three 25-Ω light bulbs and a 24 V battery are connected in a series circuit. What is the current that passes through each bulb? (a) 0.23 A (b) 0.51 A (c) 0.96 A (d) 1.6 A (e) The current will be 1.6 A in the 15-Ω bulbs and 0.96 A in the 25-Ω bulbs.

A

Which one of the following statements concerning resistors in series is true? (a) The voltage across each resistor is the same. (b) The current through each resistor is the same. (c) The power dissipated by each resistor is the same. (d) The rate at which charge flows through each resistor depends on its resistance. (e) The total current through the resistors is the sum of the current through each resistor.

B

An ac current has an rms value of 3.54 A. Determine the peak value of the current. (a) 1.25A (b) 2.50A (c) 3.75 A (d) 5.00 A (e) 7.08 A

D

Determine the length of a copper wire that has a resistance of 0.172 Ω and cross-sectional area of 1 × 10-4 m2. The resistivity of copper is 1.72 × 10-8 Ω ⋅ m. (a) 0.1m (b) 10 m (c) 100m (d) 1000 m (e) 10000m

D

Three resistors, 6.0-Ω, 9.0-Ω, 15-Ω, are connected in parallel in a circuit. What is the equivalent resistance of this combination of resistors? (a) 30Ω (b) 10Ω (c) 3.8Ω (d) 2.9Ω (e) 0.34Ω

D

Two wires A and B are made of the same material and have the same diameter. Wire A is twice as long as wire B. If each wire has the same potential difference across its ends, which one of the following statements is true concerning the current in wire A? (a) The current is one-fourth that in B. (b) The current is four times that in B. (c) The current is equal to the current in B. (d) The current is half as much as that in B. (e) It is twice as much as that in B.

D

When two capacitors are connected in series, the equivalent capacitance of the combination is 100 μF. When the two are connected in parallel, however, the equivalent capacitance is 450 μF. What are the capacitances of the individual capacitors? (a) 200μF and 250μF (b) 125μF and 325μF (c) 175 μF and 275 μF (d) 150μF and 300μF (e) 80μF and 370μF

D

Which one of the following combinations of units is equivalent to the ohm? (a) V/C (b) A/J (c) J/s (d) J•s/C2 (e) W/A

D

Which one of the following situations results in a conventional electric current that flows westward? (a) a beam of protons moves eastward (b) an electric dipole moves westward (c) a beam of electrons moves westward (d) a beam of electrons moves eastward (e) a beam of neutral atoms moves westward

D

B

How much current flows through the 2-Ω resistor? (a) 2.0A (b) 4.0 A (c) 6.0A (d) 8.7 A (e) 10.0 A

C

How much current flows through the 3-Ω resistor? (a) 2.0A (b) 4.0 A (c) 6.0A (d) 8.7 A (e) 10.0 A

C

How much energy is dissipated in the 1.8-Ω resistor in 4.0 seconds? (a) 18J (b) 28J (c) 55J (d) 64J (e) 93 J

C

How much energy is stored in the combination of capacitors shown? (a) 0.01 J (b) 0.02 J (c) 0.03 J (d) 0.04 J (e) 0.05 J

A

If t1 = 0.050 s, what is the value of t2? Note: The origin for the graph is not necessarily at t = 0 s. (a) 0.067s (b) 0.079s (c) 0.10s (d) 0.60s (e) 61 s

D

Of the five wires, which one has the smallest resistance? (a) wire A (b) wire B (c) wire C (d) wire D (e) wire E

B

Some light bulbs are connected in parallel to a 120 V source as shown in the figure. Each bulb dissipates an average power of 60 W. The circuit has a fuse F that burns out when the current in the circuit exceeds 9 A. Determine the largest number of bulbs, which can be used in this circuit without burning out the fuse. (a) 9 (b) 17 (c) 25 (d) 34 (e) 36

B

What is the current in the 3.6-Ω resistor? (a) 1.3A (b) 1.7 A (c) 2.9A (d) 3.5 A (e) 15 A

A

What is the current through the 1.8-Ω resistor? (a) 2.8A (b) 3.3 A (c) 5.6A (d) 6.9 A (e) 14 A

B

What is the current through the 3.6-Ω resistor? (a) 1.3A (b) 3.3 A (c) 6.9A (d) 7.5 A (e) 25 A

C

What is the current through the 30-Ω resistor? (a) 0.3A (b) 0.5A (c) 0.7A (d) 1A (e) 2 A

D

What is the equivalent capacitance of the combination of capacitors shown in the circuit? (a) 0.37 μF (b) 3.3 μF (c) 4.6 μF (d) 0.67 μF (e) 2.1 μF

C

What is the equivalent resistance between the points A and B? (a) 1.5 Ω (b) 4.8 Ω (c) 7.5 Ω (d) 9.4 Ω (e) 11 Ω

C

What is the equivalent resistance between the points A and B? (a) 10Ω (b) 20Ω (c) 30Ω (d) 50Ω (e) 100Ω

B

What is the equivalent resistance between the points A and B? (a) 3.8 Ω (b) 4.3 Ω (c) 5.1 Ω (d) 6.8 Ω

C

What is the equivalent resistance between the points A and B? (a) 1.5Ω (b) 4.8 Ω (c) 8.7Ω (d) 10.4 Ω (e) 11.1 Ω

D

What is the peak voltage? (a) 10V (b) 60V (c) 120 V (d) 170 V (e) 240 V

A

What is the potential drop across the 10-Ω resistor? (a) 10V (b) 20V (c) 30V (d) 60V (e) 100 V

A

What is the potential drop across the 3.5-Ω resistor? (a) 2.0V (b) 5.0V (c) 8.0V (d) 17V (e) 25V

B

What is the potential drop across the 30-Ω resistor? (a) 10V (b) 20V (c) 30V (d) 60V (e) 100 V

C

What is the resistance of the iron? (a) 24Ω (b) 7.1 Ω (c) 17 Ω (d) 12 Ω (e) 1.8Ω

B

What is the rms value of the current in this circuit? (a) 1.4A (b) 7.1A (c) 11A (d) 14A (e) 18A

A

Five resistors are connected as shown. What is the equivalent resistance between points A and B? (a) 6.8Ω (b) 9.2Ω (c) 3.4 Ω (d) 2.1Ω (e) 16Ω

C

Two resistors are arranged in a circuit that carries a total current of 15 A as shown in the figure. Which one of the entries in the following table is correct? (a) 5 A, 10 V (b) 5 A, 20 V (c) 10 A, 20 V (d) 15 A, 15 V (e) 10 A, 10 V

E

What is the current in the 2.7-Ω resistor? (a) 12A (b) 0.8 A (c) 2.2A (d) 0.4 A (e) 1.2 A

B

What is the total power dissipated in the two resistors in the circuit shown? (a) 10W (b) 15W (c) 33W (d) 67W (e) 670W

*A 10.0-μF capacitor is charged so that the potential difference between its plates is 10.0 V. A 5.0-μF capacitor is similarly charged so that the potential difference between its plates is 5.0 V. The two charged capacitors are then connected to each other in parallel with positive plate connected to positive plate and negative plate connected to negative plate.* What is the final potential difference across the plates of the capacitors when they are connected in parallel? (a) 5.0V (b) 6.7 V (c) 7.5V (d) 8.3 V (e) 10V

D

A 10-A current is maintained in a simple circuit with a total resistance of 200 Ω. What net charge passes through any point in the circuit during a 1-minute interval? (a) 200C (b) 400 C(c) 500C (d) 600 C (e) 1200C

D

A 3.0-μF capacitor is connected in series with a 4.0-μF capacitor and a 48-V battery. What quantity of charge is supplied by the battery to charge the capacitors? (a) 3.4×10-4 C (b) 7.3×10-4 C (c) 3.0×10-5 C (d) 8.2×10-5 C (e) 1.8×10-6 C

D

The resistivity of a silver wire with a radius of 5.04 × 10-4 m is 1.59 × 10-8 Ω ⋅ m. If the length of the wire is 3.00 m, what is the resistance of the wire? (a) 0.0598 Ω (b) 47.0 μΩ (c) 9.46 μΩ (d) 0.167 Ω (e) 1.88 Ω

A

Three resistors, 50-Ω, 100-Ω, 200-Ω, are connected in series in a circuit. What is the equivalent resistance of this combination of resistors? (a) 350Ω (b) 250 Ω (c) 200Ω (d) 120 Ω (e) 29Ω

A

C

A 4.5-V battery is connected to two resistors connected in series as shown in the drawing. Determine the total power dissipated in the resistors. (a) 0.033 W (b) 0.090 W (c) 0.15 W (d) 0.60 W (e) 4.7 W

*A 10.0-μF capacitor is charged so that the potential difference between its plates is 10.0 V. A 5.0-μF capacitor is similarly charged so that the potential difference between its plates is 5.0 V. The two charged capacitors are then connected to each other in parallel with positive plate connected to positive plate and negative plate connected to negative plate.* How much energy is dissipated when the two capacitors are connected together? (a) 33μJ (b) 42 μJ (c) 63μJ (d) 130 μJ (e) 560μJ

B

A 40-W and a 60-W light bulb are designed for use with the same voltage. What is the ratio of the resistance of the 60-W bulb to the resistance of the 40-W bulb? (a) 1.5 (b) 0.67 (c) 2.3 (d) 0.44 (e) 3.0

B

A 5-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 20 W, how large is the resistance? (a) 0.4Ω (b) 0.8Ω (c) 2Ω (d) 4Ω (e) 8Ω

B

Complete the following statement: The unit kilowatt ⋅ hour measures (a) current (b) energy (c) power (d) potential drop (e) voltage

B

Three parallel plate capacitors, each having a capacitance of 1.0 μF are connected in parallel. The potential difference across the combination is 100 V. What is the charge on any one of the capacitors? (a) 30 μC (b) 100 μC (c) 300 μC (d) 1000 μC (e) 3000 μC

B

When a 1500-W hair dryer is in use, the current passing through the dryer may be represented as I = (17.7 A) sin (120πt). What is the rms current for this circuit? (a) 17.7 A (b) 12.5 A (c) 85.7 A (d) 25.0 A (e) 8.85 A

B

When a light bulb is connected to a 4.5 V battery, a current of 0.16 A passes through the bulb filament. What is the resistance of the filament? (a) 440 ohms (b) 28 ohms (c) 9.3 ohms (d) 1.4 ohms (e) .72 ohms

B

A non-ideal battery has a 6.0-V emf and an internal resistance of 0.6 Ω. Determine the terminal voltage when the current drawn from the battery is 1.0 A. (a) 5.0V (b) 6.0 V (c) 5.4V (d) 6.6 V (e) 5.8V

C

Complete the following statement: A simple series circuit contains a resistance R and an ideal battery. If a second resistor is connected in parallel with R, (a) the voltage across R will decrease. (b) the current through R will decrease. (c) the total current through the battery will increase. (d) the rate of energy dissipation in R will increase. (e) the equivalent resistance of the circuit will increase.

C

The current through a certain heater wire is found to be fairly independent of its temperature. If the current through the heater wire is doubled, the amount of energy delivered by the heater in a given time interval will (a) increase by a factor of two. (b) decrease by a factor of two. (c) increase by a factor of four. (d) decrease by a factor of four. (e) increase by a factor of eight.

C

The potential difference across the ends of a wire is doubled in magnitude. If Ohm's law is obeyed, which one of the following statements concerning the resistance of the wire is true? (a) The resistance is one half of its original value. (b) The resistance is twice its original value. (c) The resistance is not changed. (d) The resistance increases by a factor of four. (e) The resistance decreases by a factor of four.

C

Three parallel plate capacitors, each having a capacitance of 1.0 μF are connected in parallel. The potential difference across the combination is 100 V. What is the equivalent capacitance of this combination? (a) 0.3μF (b) 1μF (c) 3μF (d) 6μF (e) 30μF

C

Which one of the following quantities can be converted to kilowatt ⋅ hours (kWh)? (a) 2.0 A (b) 8.3 V (c) 5.8 J (d) 9.6 W (e) 6.2 C/V

C

Which one of the following statements concerning resistance is true? (a) The resistance of a semiconductor increases with temperature. (b) Resistance is a property of resistors, but not conductors. (c) The resistance of a metal wire changes with temperature. (d) The resistance is the same for all samples of the same material. (e) The resistance of a wire is inversely proportional to the length of the wire.

C

Which one of the following statements concerning superconductors is false? (a) Below its critical temperature, the resistivity of a superconductor is zero Ω-m. (b) Critical temperatures for some superconductors exceed100K. (c) All materials are superconducting at temperatures near absolute zero kelvin. (d) A constant current can be maintained in a superconducting ring for several years without an emf. (e) Superconductors are perfect conductors.

C

Which one of the following statements is true concerning capacitors of unequal capacitance connected in series? (a) Each capacitor holds a different amount of charge. (b) Theequivalentcapacitanceofthecircuitisthesumoftheindividualcapacitances. (c) The total voltage supplied by the battery is the sum of the voltages across each capacitor. (d) Thetotalpositivechargeinthecircuitisthesumofthepositivechargesoneachcapacitor. (e) The total voltage supplied by the battery is equal to the average voltage across all the capacitors.

C

E

Determine the equivalent resistance for this circuit. (a) 50Ω (b) 120Ω (c) 29Ω (d) 5Ω (e) 12Ω

A

Determine the power dissipated by the 40-Ω resistor in the circuit shown. (a) 3.6W (b) 4.5W (c) 9.0 W (d) 14W (e) 27W

A 4-A current is maintained in a simple circuit with a total resistance of 2 Ω. How much energy is delivered in 3 seconds? (a) 3 J (b) 6 J (c) 12 J (d) 24 J (e) 96 J

E

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 7.5-Ω resistor. What is the internal resistance of the battery? (a) 3.2Ω (b) 0.27 (c) 1.2Ω Ω (d) 0.75 Ω (e) 0.68Ω

E

A computer monitor uses 2.0 A of current when it is plugged into a 120 V outlet. The monitor is never turned off. What is the yearly cost of operating the monitor if the cost of electricity is $0.12/kWh? (a) $14 (b) $21 (c) $98 (d) $170 (e) $250

E

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? (a) 0.13Ω (b) 220Ω (c) 18Ω (d) 8.0 Ω (e) 96Ω

E

How many electrons flow through a battery that delivers a current of 3.0 A for 12 s? (a) 4 (b) 36 (c) 4.8×1015 (d) 6.4 × 1018 (e) 2.2×1020

E

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? (a) The current through A and B will increase. (b) ThevoltageacrossAandBwillincrease. (c) The voltage across the entire circuit will increase. (d) Thepowerusedbytheentirecircuitwillincrease. (e) The current through the entire circuit will decrease.

E

B

The largest potential difference is across which resistor(s)? (a) the 10-Ω resistor (b) the 20-Ω resistor (c) the 30-Ω resistor (d) the 60-Ω resistor (e) It is the same and the largest for the 30-Ω and 60-Ω resistors.

D

The smallest current passes through which resistor(s)? (a) the 10-Ω resistor (b) the 20-Ω resistor (c) the 30-Ω resistor (d) the 60-Ω resistor (e) It is the same and the largest for the 30-Ω and 60-Ω resistors.

D

Three resistors and two 10.0-V batteries are arranged as shown in the circuit diagram. Which one of the following entries in the table is correct? battery 1 battery 2 (a) 2.5 W 2.5 W (b) 4.0 W 1.0 W (c) 1.0 W 1.0 W (d) 1.0 W 4.0 W (e) 4.0 W 4.0 W

E

Three resistors and two batteries are connected as shown in the circuit diagram. What is the magnitude of the current through the 12-V battery? (a) 0.15 A (b) 0.82 A (c) 0.30 A (d) 0.67 A (e) 0.52 A

B

Three resistors are connected in a circuit as shown. Using Kirchhoff's rules, determine the current in one of the 16-Ω resistors. (a) 0.50 A (b) 0.75 A (c) 1.0 A (d) 1.3 A (e) 2.0 A

D

What amount of energy is dissipated in the 2.7-Ω resistor in 9.0 seconds? (a) 15 J (b) 24 J (c) 29 J (d) 36 J (e) 52 J

C

What is the approximate average power dissipated in the iron? (a) 450W (b) 600 W (c) 850W (d) 1200 W (e) 1700 W

A

Which one of the five wires has the largest resistance? (a) wire A (b) wire B (c) wire C (d) wire D (e) wire E

E

Which one of the following circuits has the largest resistance?

E

Which one of the following statements is the best conclusion based on the data? (a) The resistance of the wire is 20 Ω. (b) ThewiredoesnotobeyOhm'slaw. (c) The current in the wire is directly proportional to the applied potential difference. (d) ThewireobeysOhm'slawovertherangeofpotentialdifferencesbetween5and30V. (e) The wire obeys Ohm's law over the range of potential differences between 5 and 20 V.

E

Which one of the wires carries the smallest current when they are connected to identical batteries? (a) wire E (b) wire D (c) wire C (d) wire B (e) wire A