Reading Quiz• Which will draw more current, connecting a 9

volt battery in a circuit with a 1 Ohm resistance or with a 100 Ohm resistance?

• 1 Ohm

• 100 Ohms

• Same current for both

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Chapters 10,11,12,13,14,15

Summary of electric circuits:

1. The amount of current is the same at every place in a series circuit; I=q/t.

2. The power provided by the battery (P=IV) is exactly equal to the power dissipated in the resistors (P=I2R).

3. Ohm’s Law applies to resistors: V=IR

4. Series circuit: effective R = R1 + R2 + R3

5. Parallel circuit: effective R is

6. Charge is conserved

7. Current is conserved

8. The voltage drops around a circuit is zero

1

Reff

1

R1

1

R2

1

R3

Question 1

How much current I runs through this circuit?

A. 0.333 Amps

B. 0.500 A

C. 1.000 A

D. 2.250 A

E. 3.000 A

1.5 V

Choose the answer closest to your result.

Question 2

How much current I is generated by the battery?

A. 0.333 Amps

B. 0.500 A

C. 1.000 A

D. 2.250 A

E. 3.000 A

1.5 V

Choose the answer closest to your result.

Question 3

What is the voltage drop across the 2 Ohm resistor?

A. Zero

B. The same as the drop across the other resistor.

C. More than across the other resistor.

D. Less than across the other resistor.

1.5 V

VA B

switch

V

+Question 4:

This circuit has 2 identical light bulbs. After the switch is closed,

A. A is brighter than B.

B. A is dimmer than B.

C. A & B are equally bright, but dimmer than A was before.

D. A & B are equally bright, but brighter than A was before.

E. A & B are equally bright, and the same as A was before.

VA B

switch

V

+

C

Question 5:

Light bulbs A, B, & C are identical. After the switch is closed,

A. A & C both get brighter.

B. A & C both get dimmer.

C. A is brighter, and C is dimmer.

D. A is dimmer, and C is brighter.

E. A & C stay the same.

Question 6

For three resistors in parallel, choose the correct statement:

EMF

volts 1 2 3

A. The current and the voltage across all three are the same.

B. The voltage drop and the power dissipated across all three are the same.

C. The energy given up per electron is the same for all three.

D. The current through one resistor is the same as the current through the battery.

By placing all electric items in parallel they receive the same voltage

By placing electrical items in series they receive the same current

A volt meter has a high resistance so take very little current

Fig. 13.13

An Amp meter has very little resistance so take very little voltage

Question 14

If R1=10 ohms, R2=5 ohms and R3=10 ohms what is the total resistance of the circuit?

Energy source => Potential Energy => Kinetic Energy => Heat

Power = Energy/unit timeP=V * IP= (I*R) *I= I2 R

Units of PowerWATTS = Joules/second

Note: Energy = power * timeWe purchase electrical energy by the Kilowatt-hr

If the resistance of the light is 20 ohms what is the power given off by the light?

If the light were to be on for 24 hours how much energy would be used up?

Summary 5

Fig. 13.18

What is the current that flows in this circuit at point B?

1.)288 amps2.) 1.5 amp3.) 0.1 amp4.) 0.5 amp5.) 0.03 amps

B.

By placing all electric items in parallel they receive the same voltage

By placing electrical items in series they receive the same current