Ch. 23 Electric CurrentCh. 23 Electric Current

Clicker ActivitiesClicker Activities

TaskTask

You will be shown four different You will be shown four different arrangements of light bulbs connected to arrangements of light bulbs connected to batteries with conducting wires. The batteries with conducting wires. The arrangements will vary with their being arrangements will vary with their being between 0 and 4 light bulbs connected in between 0 and 4 light bulbs connected in series. Assume all pieces in the circuit series. Assume all pieces in the circuit behave perfectly. A voltmeter will be behave perfectly. A voltmeter will be used to measure the potential difference used to measure the potential difference between the terminals of the battery.between the terminals of the battery.

V1

V3

V2

V4

Rank the potential difference measured Rank the potential difference measured between the two battery terminals from the between the two battery terminals from the greatest to the least. If there are any ties greatest to the least. If there are any ties indicate them.indicate them.

A.A. VV11 > V > V22 > V > V33 > V > V44

B.B. VV44 > V > V33 > V > V22 > V > V11

C.C. VV11 = V = V44 > V > V22 = V = V33

D.D. VV11 = V = V22 = V = V33 = V = V44

E.E. Cannot be determinedCannot be determined

What was the reason that you What was the reason that you ranked them that way?ranked them that way?

A.A. The more resistors, the more voltage The more resistors, the more voltage the battery suppliesthe battery supplies

B.B. The more resistors the less voltage a The more resistors the less voltage a battery suppliesbattery supplies

C.C. The voltage is used by the first light The voltage is used by the first light bulb, then the next …bulb, then the next …

D.D. The bulbs on the end use up the The bulbs on the end use up the voltage firstvoltage first

E.E. Ideal batteries always provide the Ideal batteries always provide the same voltagesame voltage

How confident are you about your How confident are you about your answer?answer?

A.A. I know I’m rightI know I’m right

B.B. I’m pretty sureI’m pretty sure

C.C. NeutralNeutral

D.D. I’m mostly guessingI’m mostly guessing

E.E. I’m completely guessingI’m completely guessing

Task – A student builds a series circuit Task – A student builds a series circuit with a battery and three identical light with a battery and three identical light bulbs. She correctly determines that the bulbs. She correctly determines that the circuit will draw .3 A. Between each circuit will draw .3 A. Between each circuit element she inserts an ammeter. circuit element she inserts an ammeter. Before closing the switch she predicts Before closing the switch she predicts what the reading of each ammeter will what the reading of each ammeter will be as shown in the next slide. What if be as shown in the next slide. What if anything is wrong with her prediction?anything is wrong with her prediction?

.3 A

.2 A

.1 A

0.0 A

What if anything is wrong with the predicted What if anything is wrong with the predicted values of the ammeter readings?values of the ammeter readings?

A.A. Nothing the predictions are correctNothing the predictions are correct

B.B. The values are correct but the order of the The values are correct but the order of the readings should be reversedreadings should be reversed

C.C. The readings should all be the sameThe readings should all be the same

D.D. The readings should be greater on the outer The readings should be greater on the outer ammeters ammeters

E.E. The readings should be greater in the middleThe readings should be greater in the middle

How confident are you about your How confident are you about your answer?answer?

A.A. I know I’m rightI know I’m right

B.B. I’m pretty sureI’m pretty sure

C.C. NeutralNeutral

D.D. I’m mostly guessingI’m mostly guessing

E.E. I’m completely guessingI’m completely guessing

Several Circuits will be modified Several Circuits will be modified by changing the number of light by changing the number of light bulbs. Your task will be to bulbs. Your task will be to predict and explain how adding predict and explain how adding the light bulbs will change the the light bulbs will change the reading on the ammeter and the reading on the ammeter and the brightness of each bulb.brightness of each bulb.

Consider the following circuit. An Consider the following circuit. An additional resistor will be added in additional resistor will be added in series. Answer the following series. Answer the following questions.questions.

What will happen to the reading What will happen to the reading on the ammeter?on the ammeter?

A.A. It will increaseIt will increase

B.B. It will decreaseIt will decrease

C.C. It will remain the sameIt will remain the same

D.D. Some other answerSome other answer

What was your reason?What was your reason?

A.A. The resistance went up so less The resistance went up so less currentcurrent

B.B. More light bulbs so more More light bulbs so more currentcurrent

C.C. The battery remains the same The battery remains the same so no changeso no change

D.D. Some other answerSome other answer

What will happen to the brightness What will happen to the brightness of each light bulb when the third one of each light bulb when the third one is added?is added?

A.A. It will remain the same.It will remain the same.

B.B. It will increaseIt will increase

C.C. It will decreaseIt will decrease

D.D. Some other answerSome other answer

Consider the following circuit. A 3Consider the following circuit. A 3rdrd light bulb will be added in parallel. light bulb will be added in parallel. Answer the following questions.Answer the following questions.

What will happen to the reading What will happen to the reading on the ammeter?on the ammeter?

A.A. It will increaseIt will increase

B.B. It will decreaseIt will decrease

C.C. It will remain the sameIt will remain the same

D.D. Some other answerSome other answer

What was your reason?What was your reason?

A.A. The resistance went up so The resistance went up so less currentless current

B.B. More light bulbs so more More light bulbs so more currentcurrent

C.C. The battery remains the same The battery remains the same so no changeso no change

D.D. Some other answerSome other answer

What will happen to the brightness What will happen to the brightness of each light bulb when the third one of each light bulb when the third one is added?is added?

A.A. It will remain the same.It will remain the same.

B.B. It will increaseIt will increase

C.C. It will decreaseIt will decrease

D.D. Some other answerSome other answer