Ch. 3 Electricity

Question 1

The resistance in a wire decreases as its:

Answer 1

Diameter increases

Question 2

If the total resistance in a circuit is 9 ohms and the total voltage is 3 volts, the current it:

Answer 2

1/3 amperes.

V=IR

Question 3

If a DC circuit is:

a. In series, the currents are different for each component
b. In series, the voltages are the same for each compartment
c. In parallel, the currents are equal for all paths of the circuit
d. In parallel, the voltages are equal for all paths of the circuit

Answer 3

d. In parallel, the voltages are equal for all paths of the circuit

Question 4

Electric current is defined as:

Answer 4

Charge/time

Question 5

Coulomb’s law of electrical forces is mathematically described as:

Answer 5

F=q1q2/r^2

Question 6

A current of 2 amperes and a resistance of 8 ohms require what voltage in a series circuit?

Answer 6

16 volts

V=IR

Question 7

When an electric current flows through a wire with resistance, energy is:

Answer 7

liberated as heat

Question 8

Ohm’s law is mathematically described as:

Answer 8

R=V/I

or V=IR

Question 9

Electric potential is measured in:

Answer 9

Volts

Question 10

Electric insulators:

Answer 10

Inhibit movement of electrical charge

Question 11

If 20 volts of potential difference causes a current of 5 amperes to flow in a parallel circuit, the resistance produced is:

Answer 11

4 ohms

V=IR

Question 12

When the atomic valence and conductance bands overlap,

Answer 12

Electrical flow easily occurs

Question 13

A charge would lost most of its energy when it passes through a:

Answer 13

Resistor

Question 14

If the distance between two electrical charges is doubled, the force between them is:

Answer 14

Decreased by 1/4

Question 15

A 100 W light bulb with an amperage of 0.91 A is operating at a potential difference of:

Answer 15

110 volts

Question 16

An ampere is:

Answer 16

Coulomb/sec

Question 17

Resistance is:

Answer 17

The opposition to the flow of electrons

Question 18

The charge on each of two objects is doubled, and they are moved twice as far apart. The force between them is:

Answer 18

Unchanged

Question 19

A circuit has a current of 2 amperes and a resistance of 4 ohms. The maximum power that can be delivered is:

Answer 19

16 Watts
V=IR
P=IV
or P=I^2(R)

Question 20

The unit of electrical power is:

Answer 20

Watt

Question 21

If 10 coulombs pass a point in 2 seconds, the current is:

Answer 21

5 amps (Couloumb/second)

Question 22

In a parallel circuit,

Answer 22

The voltage is equal across all branches of the circuit.

Question 23

In a battery circuit with several resistors of different values connected in series,

a. The voltage drop is the same across all the resistors
b. The current through each resistor is different
c. The power dissipated through each resistor is the same
d. None of the above

Answer 23

d. None of the above

Question 24

If a conductor is positively charged, it:

Answer 24

Is deficient in electrons

Question 25

The milliampere (mA) is a unit of:

Answer 25

Current

Question 26

Neon lights illustrate the fact that electrons will flow:

Answer 26

In a gaseous environment

Question 27

All of the following choices are considered good metallic electrical conductors EXCEPT:

a. Gold
b. Silver
c. Carbon
d. Copper

Answer 27

c. Carbon

Question 28

The current flow from a dry cell battery source would be:

Answer 28

Direct current

Question 29

Electrical components possess a negative and a positive side. This polarity permits the application of:

Answer 29

An electromotive force (emf) to enable current flow

Question 30

When 6.24 x 10^18 electrons travel in one second producing a joule (j) of work,

Answer 30

One volt has been created