Question 1

Your flashlight has three identical 1.5 Volt batteries in it, arranged in a chain to give a total of 4.5 Volts. Current passes first through the first battery, then through the second battery, then through the third, on its way to the bulb. When you operate the flashlight, the batteries provide power to the flowing charges and they gradually use up their chemical potential energy. Which battery will run out of chemical potential energy first?

Accepted Answer

In a series circuit, like the one described for the flashlight, all components (including batteries) share the same current. Therefore, all three batteries will deplete at the same rate and run out of chemical potential energy simultaneously.

Question 2

A rocking chair has damaged the cord of your desk lamp. One of the two wires in the cord is completely cut in half and cannot carry any current. However, the other wire still connects the lamp to the electric socket. If you turn on the lamp,

Accepted Answer

For a lamp to work, current must flow in a complete circuit from the power source, through the lamp, and back to the power source. If one of the wires is completely cut, the circuit is open, and no current can flow, so the lamp will not light up.

Question 3

You have just put fresh batteries in your flashlight and it is working nicely. Now suppose that you remove both of the batteries and reinsert them backward. Despite the fact that the both batteries are reversed, they connect properly to one another and to the flashlight, so that there are no connection problems in the flashlight. As the result of this battery reversal, the flashlight will

Accepted Answer

The flashlight will work normally because the batteries are still connected to the flashlight in the same way, even though they are reversed. The only difference is that the polarity of the batteries is reversed, which means that the positive terminal of one battery is now connected to the negative terminal of the other battery. This does not affect the operation of the flashlight because the flashlight only cares about the voltage difference between the two batteries, which is the same regardless of which way the batteries are connected.

Question 4

You have just put fresh batteries in your flashlight and it is working nicely. Now suppose that you remove one of the batteries and reinsert it backward. Despite the fact that the one battery is reversed, both batteries connect properly to one another and to the flashlight, so that there are no connection problems in the flashlight. As the result of this battery reversal, the flashlight will

Accepted Answer

Reversing one battery in a series circuit, like in a flashlight, causes the voltages to oppose each other, preventing the circuit from completing and the flashlight from lighting up.

Question 5

You drop your boom box and one of the two wires that connects the batteries to the electronics is severed. While you might hope that the device would continue working at half its normal volume, you find that it does not work at all. This is because both wires are necessary for the boom box to operate. One wire carries

Accepted Answer

In a circuit, one wire is needed to carry the current to the device (in this case, the electronics of the boom box), and the other wire is necessary to complete the circuit by returning the current back to the battery. This completes the electrical circuit, allowing the device to function.

Question 6

A car stereo draws 24 A of current at voltage 12 V. What power does it use?

Accepted Answer

The power used by the car stereo can be calculated using the formula Power (P) = Voltage (V) * Current (I), which gives P = 12V * 24A = 288W.

Question 7

A power line carries current 10 A and has resistance 2.0 $\Omega$. What is the voltage drop across the line?

Accepted Answer

The voltage drop across the line can be calculated using Ohm's Law, V = IR, where I = 10 A and R = 2.0 Ω, thus V = 10 A * 2.0 Ω = 20 V.

Question 8

Your new toaster has two separate toasting units, each of which consumes 600 watts of power when it is in use. When you operate one unit, a current of 5 amperes flows through the wiring in your home and the wires waste about 1 watt of power handling that current. If you operate both toasting units at once, your toaster consumes 1200 watts and the current flowing through the wiring in your home doubles to 10 amperes. How much power will the wires in your home waste now?

Accepted Answer

The power wasted in the wires is proportional to the square of the current (P = I^2 * R, where P is power, I is current, and R is resistance). If 1 watt is wasted with 5 amperes, then with 10 amperes (double the current), the power wasted will be 4 times as much (since 10^2 / 5^2 = 4), resulting in 4 watts wasted.

Question 9

A power line carries current 10 A and has resistance 2.0 $\Omega$. What is the power loss as heat in the line?

Accepted Answer

The power loss due to resistance in a conductor can be calculated using the formula P = I^2 * R, where P is the power loss in watts, I is the current in amperes, and R is the resistance in ohms. Substituting the given values, P = 10^2 * 2 = 100 * 2 = 200 W.

Question 10

Two 1.5-V batteries placed end-to-end power a flashlight. If the current in the circuit is 0.6 A, what is the resistance in the bulb?

Accepted Answer

The resistance in the bulb can be calculated using Ohm's law: R = V/I. In this case, the voltage is 3 V (since the two batteries are placed end-to-end) and the current is 0.6 A. Therefore, the resistance is R = 3 V / 0.6 A = 5 $\Omega$.

Question 11

A 60 watt, 120 volt light bulb is designed to operate at a 1/2 A current. If you screw this bulb into a fixture that is powered by very long thin wires it will glow more dimly than intended because the voltage drop across the bulb will be

Accepted Answer

Long, thin wires have higher resistance, which causes a voltage drop before the current reaches the bulb. This results in both a lower voltage across the bulb and a lower current through it than designed.

Question 12

You are stranded on an Arctic wasteland with your physics class. Forget food and survival - you're playing with circuits to pass the long winter months. You have two batteries, some wire and two light bulbs. If you must use both batteries and both bulbs how would you hook them up so as to get
-maximum brightness

Accepted Answer

The answer of You are stranded on an Arctic wasteland...

Question 13

You are stranded on an Arctic wasteland with your physics class. Forget food and survival - you're playing with circuits to pass the long winter months. You have two batteries, some wire and two light bulbs. If you must use both batteries and both bulbs how would you hook them up so as to get
-minimum (not zero!) brightness?

Accepted Answer

The answer of You are stranded on an Arctic wasteland...

Question 14

You are stranded on an Arctic wasteland with your physics class. Forget food and survival - you're playing with circuits to pass the long winter months. You have two batteries, some wire and two light bulbs. If you must use both batteries and both bulbs how would you hook them up so as to get
-Suppose one battery delivers 3V and one bulb has a resistance of 0.2 Ω. Please calculate the power output of this one - bulb circuit and the current through the bulb.

Accepted Answer

The answer of You are stranded on an Arctic wasteland...

Question 15

Suppose you have a 12V battery supplying current to a 6Ω resistor.
 
-Calculate the current through the resistor.

Accepted Answer

The answer of Suppose you have a 12V battery supplying...

Question 16

Suppose you have a 12V battery supplying current to a 6Ω resistor.
 
-What is the value of the power being dissipated by the resistor?

Accepted Answer

The answer of Suppose you have a 12V battery supplying...

Question 17

Suppose you have a 12V battery supplying current to a 6Ω resistor.
 
-If you trace electrons around the circuit, they actually go from high voltage to low voltage through the battery. Please explain why this takes energy from the battery.

Accepted Answer

The answer of Suppose you have a 12V battery supplying...

Question 18

Suppose you have a 12V battery supplying current to a 6Ω resistor.
 
-As the current (moving charge) goes through the resistor what is happening to its potential energy?

Accepted Answer

The answer of Suppose you have a 12V battery supplying...

Question 19

You are stranded on an island, passing time by making electric circuits using two batteries and two bulbs! This time, however your supplies are running dangerously low and you need to make the circuits where the batteries will last (retain their energy) the longest.
-Please explain how you would connect the circuits so as to achieve longest battery life.

Accepted Answer

The answer of You are stranded on an island, passing...

Question 20

You are stranded on an island, passing time by making electric circuits using two batteries and two bulbs! This time, however your supplies are running dangerously low and you need to make the circuits where the batteries will last (retain their energy) the longest.
-The battery in any circuit actually moves electrons from high voltage to low voltage when it is supplying power. Please explain why this movement takes energy from the battery.

Accepted Answer

The answer of You are stranded on an island, passing...

Quiz 10: Electricity

A rocking chair has damaged the cord of your desk lamp. One of the two wires in the cord is completely cut in half and cannot carry any current. However, the other wire still connects the lamp to the electric socket. If you turn on the lamp,

A car stereo draws 24 A of current at voltage 12 V. What power does it use?

A power line carries current 10 A and has resistance 2.0 $\Omega$ . What is the voltage drop across the line?

A power line carries current 10 A and has resistance 2.0 $\Omega$ . What is the power loss as heat in the line?

Two 1.5-V batteries placed end-to-end power a flashlight. If the current in the circuit is 0.6 A, what is the resistance in the bulb?

A 60 watt, 120 volt light bulb is designed to operate at a 1/2 A current. If you screw this bulb into a fixture that is powered by very long thin wires it will glow more dimly than intended because the voltage drop across the bulb will be

Suppose you have a 12V battery supplying current to a 6Ω resistor. -Calculate the current through the resistor.

Suppose you have a 12V battery supplying current to a 6Ω resistor. -What is the value of the power being dissipated by the resistor?

Suppose you have a 12V battery supplying current to a 6Ω resistor. -If you trace electrons around the circuit, they actually go from high voltage to low voltage through the battery. Please explain why this takes energy from the battery.

Suppose you have a 12V battery supplying current to a 6Ω resistor. -As the current (moving charge) goes through the resistor what is happening to its potential energy?

Quiz 10: Electricity

A rocking chair has damaged the cord of your desk lamp. One of the two wires in the cord is completely cut in half and cannot carry any current. However, the other wire still connects the lamp to the electric socket. If you turn on the lamp,

A car stereo draws 24 A of current at voltage 12 V. What power does it use?

A power line carries current 10 A and has resistance 2.0 Ω\OmegaΩ . What is the voltage drop across the line?

A power line carries current 10 A and has resistance 2.0 Ω\OmegaΩ . What is the power loss as heat in the line?

Two 1.5-V batteries placed end-to-end power a flashlight. If the current in the circuit is 0.6 A, what is the resistance in the bulb?

A 60 watt, 120 volt light bulb is designed to operate at a 1/2 A current. If you screw this bulb into a fixture that is powered by very long thin wires it will glow more dimly than intended because the voltage drop across the bulb will be

Suppose you have a 12V battery supplying current to a 6Ω resistor. -Calculate the current through the resistor.

Suppose you have a 12V battery supplying current to a 6Ω resistor. -What is the value of the power being dissipated by the resistor?

Suppose you have a 12V battery supplying current to a 6Ω resistor. -If you trace electrons around the circuit, they actually go from high voltage to low voltage through the battery. Please explain why this takes energy from the battery.

Suppose you have a 12V battery supplying current to a 6Ω resistor. -As the current (moving charge) goes through the resistor what is happening to its potential energy?

A power line carries current 10 A and has resistance 2.0 $\Omega$ . What is the voltage drop across the line?

A power line carries current 10 A and has resistance 2.0 $\Omega$ . What is the power loss as heat in the line?