Physics

Suppose that we use an uncoated metal clamp to hold the wires in place in the battery-and-bulb circuit shown. How bright will the bulb be?

much dimmer than without the clamp

A 9 ohm resistor and a 16 ohm resistor are connected in series in a circuit with a 5.0 volt battery. Assuming negligible internal resistance in the battery, the current in the 16 ohm resistor will be

0.20A

An ohm is equal to which of these?

A volt per ampere

What is the best way to ensure that a 40 watt bulb and a 60 watt bulb have the same voltage applied to them?

Connect the bulbs in parallel with the power supply

Ohm's Law, in symbols, is ΔV = _____________.

DeltaV IxR?

Consider the circuit shown in the diagram, where the wires are connected to either side of a wooden block as well as to the lightbulb. Will the lightbulb light in this arrangement?

No

Is electrical energy the same as electric power?

No

A 48-Ω resistor and a 28-Ω resistor are connected in series to a 12-V battery of negligible resistance. What is the current flowing through each resistor? (You must provide an answer before moving to the next part.)

Rseries=R1+R2=48 Ω+28 Ω=76 Ω I=12V/76Ω=0.1579 A

Four 38-Ω resistors are connected in series to a 18-V battery of negligible internal resistance. Calculate the current flowing through each resistor. (You must provide an answer before moving to the next part.)

The current flowing through each resistor is Rseries= R1+ R2+ R3 +R4=4×38 Ω Rseries=152 Ω I=18V/152 Ω=0.1184 A

A 6-V battery in a simple circuit produces a current of 2.4 A through the circuit. How much power is being delivered by the battery?

The power delivered by the battery is 14.4W P=V×I=6 V×2.4 A

A 8-V battery in a simple circuit produces a current of 2.2 A through the circuit. How much power is being delivered by the battery?

The power delivered by the battery is 17.6W P=V×I=8 V×2.2 A

Three identical resistors can be connected in any combination. It's not necessary to include all three in any given combination. The number of distinct values of resistance that can be made is

five

A resistor R is connected across a battery of negligible internal resistance. If the resistance of R is doubled, the current in R will be __________.

half

When an axon is stimulated a voltage spike is created. What happens to the voltage spike after it is created?

it travels down the axon

When a battery is being used in a circuit, how will the voltage across its terminals be different from when no current is being drawn from the battery?

it will be less when it is being used

In the circuit diagram shown, R1, R2 and R3 are three resistors of different values. R3 is greater than R2, and R2 is greater than R1. ε is the electromotive force of the battery whose internal resistance is negligible. If we disconnect R2 how will the current through R3 change?

it will decrease

The standard unit for electric current is ____________.

ampere

The potential difference across the terminals of a storage battery not connected in any circuit is observed to be 12 V. When it is connected to an external resistance the potential difference across the terminals is observed to be 11 V while the current in the external resistance is 3 A. What is the internal resistance of the battery?

0.33 ohm

A student finds three resistors in the lab: a two ohm, a five ohm, and a 10 ohm resistor. The smallest value of resistance that the student can make using any one or any combination of the three resistors is ____________ ohms.

1.25

A heater is rated to dissipate 2880 W when connected to a 120 V source. The current drawn by the device is

24A

An iPod battery is rated at 3.7 volts and operates its iPod and earbuds with a direct current of 865 milliamps. What is the power rating of this iPod?

3.2W

A current of 9.5 A flows through a battery for 3 minutes. How much charge passes through the battery in that time?

A charge of 1710 C passes through the battery in 3 minutes. q=(9.5 A)×(180s)=1710 C

A current of 5 A flows through a battery for 3 minutes. How much charge passes through the battery in that time?

A charge of 900 C passes through the battery in 3 minutes. q=It

You have exactly 4 resistors: one 3 Ω, one 4 Ω, one 5 Ω, and one 6 Ω. How can you combine these to make a 2 Ω resistor? (The symbol Ω stands for "ohm.")

Connect the 3 Ω resistor in parallel with the 6 Ω resistor

A 48-Ω resistor and a 28-Ω resistor are connected in series to a 12-V battery of negligible resistance. What is the voltage difference across each resistor?

I=12 V/76 Ω=0.1579 A The value of v1 across a 48-Ω resistor is 7.5789 V. v1=IR1=0.1579 A×48Ω The value of v2 across a 28-Ω resistor is 4.4211 V. v2=IR2=0.1579 A×28Ω

A 105-W light bulb operates on an effective ac voltage of 110 V. Calculate the resistance of the light bulb using Ohm's law.

I=P/V=105 W/110 V I=0.9545 A R=V/I=110 V/0.9545A R=115.2381 Ω The resistance of the light bulb is 115.2381

Resistors of 10 ohms, 20 ohms, and 30 ohms are connected in series with a battery. The 10 ohm resistor is closest to the positive terminal and the 30 ohm resistor is closest to the negative terminal. What happens as the current flows through this circuit?

None of the resistors consume current

A 80-Ω resistor has a voltage difference of 12 V across its leads. What is the power being dissipated in this resistor?

P=V×I=12V×0.15A P=1.8 W The power dissipated is 1.8

Three resistors - R1 = 16 Ω, R2 = 22 Ω, and R3 = 26 Ω are connected to a 12-V battery as shown in the figure. The internal resistance of the battery is negligible. What is the current through the 16-Ω resistor? (You must provide an answer before moving to the next part.)

R=R1+R2+R3=16 Ω+22 Ω+26 Ω R=64 Ω I=VR=12 V/64 Ω I=0.1875 A

Three resistors - R1 = 19 Ω, R2 = 28 Ω, and R3 = 29 Ω are connected to a 12-V battery as shown in the figure. The internal resistance of the battery is negligible. What is the current through the 19-Ω resistor?

The current is 0.158A V/Rtotal=I

Three identical resistors, where R1 = 52 Ω, are connected in parallel with one another as shown. Then the parallel combination is connected to a 12-V battery whose internal resistance is negligible. How much current flows through each resistor in the combination?

The current that flows through each resistor is 0.2308A I=V/R1=12V/52 Ω I=0.2308 A

A 80-Ω resistor has a voltage difference of 12 V across its leads. What is the current through the resistor? (You must provide an answer before moving to the next part.)

The current through the resistor is 0.15A I=V/R=12V/80 Ω

A charge of 28 C passes at a steady rate through a resistor in 7 s. Determine the current through the resistor.

The current through the resistor is 4 I=q/t=28C/7s=4 A

A clothes dryer uses 7150 W of power when connected to a 220-V ac line. How much current does the dryer draw from the line?

The dryer draws a current of 32.5A I=P/V=7150W/220 V

Three resistors of 15 Ω, 6 Ω, and 10 Ω are connected in parallel with one another. What is the equivalent resistance of this combination?

The equivalent resistance of this combination is 3ohm

Three resistors of 15 Ω, 12 Ω, and 12 Ω are connected in parallel with one another. What is the equivalent resistance of this combination?

The equivalent resistance of this combination is 4.29 Ohm

A 105-W light bulb operates on an effective ac voltage of 110 V. Calculate the resistance of the light bulb using Ohm's law.

The resistance of the light bulb is 115.24 Ohm

A toaster draws a current of 10 A when it is connected to a 110-V ac line. What is the power consumption of this toaster? (You must provide an answer before moving to the next part.)

The toaster consumes a power of 1100W P=V×I=110V×10A P=1100W

Four 38-Ω resistors are connected in series to a 18-V battery of negligible internal resistance. Determine the voltage difference across each resistor.

The voltage difference across each resistor is V=IR=(0.1184 A)×(38 Ω)=4.5 V

Four 46-Ω resistors are connected in series to a 18-V battery of negligible internal resistance. Determine the voltage difference across each resistor.

The voltage difference across each resistor is 4.5V

In which situation, if either, does the electrical signal travel fastest?

in an electrical wire

In which setup would it make the most sense to connect a fuse or circuit breaker with other elements in a circuit?

in series

A resistor R is connected across a battery of negligible internal resistance. If the resistance of R is cut in half, the power dissipated in R will ______________ (indicate change, if any).

increase

Which, if either, is larger in a simple battery-and-bulb circuit?

neither; the current is the same at both places

A one ohm, a two ohm, and a three ohm resistor are connected in parallel in an electric circuit: The resistor dissipating the most power will be the ____________ ohm resistor.

one

When a nerve cell fires in your big toe, it is an interaction of positive and negative ions in the membrane of the nerve cell. This membrane has structural similarities to

oppositely charged parallel plates.

Two identical lightbulbs are installed in two sockets connected in parallel and power is then applied to the combination so that both bulbs light. If one of the bulbs is then removed from its socket, the other one will

remain equally bright.

In the circuit shown, the circle with an A in it represents an ammeter. Which of these statements is correct?

the meter will draw a significant current from the battery