Circuits

For potential difference to exist, there must be electron flow.

False

conductors inhibit flow while insulators promote flow

False

As the length of a conductor increases, the resistance increases.

True

Electrons flow from greatest potential difference to least potential difference.

True

What is Ohm's law

V=IR

__________ helps the electrons make the jump form the cathode to the anode side.

Voltage

A circuit has a current of 2 amperes and a resistance of 4 ohms. The maximum power that can be delivered is a) 16 watts. b) 8 watts. c) 2 watts. d) 1/2 watt.

a) 16 watts

What is the total resistance of a circuit if it contains resistances of 110 Ohms, 26.2 Ohms, and 14 Ohms in a parallel circuit? a) 8.4 Ohms b) 150.2 Ohms

a) 8.4 Ohms

An ampere is a) coulomb/sec. b) (coulomb)(sec). c) (volt)(ohm). d) ohm/volt.

a) coulomb/sec

The resistance in a wire decreases as its diameter a) increases. b) decreases. c) remains the same. d) none of the above

a) increases

A charge would lose most of its energy when it passes through a a) resistor. b) battery. c) generator. d) all of the above

a) resistor

Resistance is a) the opposition to the flow of electrons. b) the opposition to the generation of electromotive force. c) the location of storage of electrons. d) measured in amperes.

a) the opposition to the flow of electrons

Where is the kV selector

autotransformer

An alternative means of expressing 500 mA and 80 kVp is: a) 5 Amps, 800 Volts b) 0.5 Amps, 80,000 Volts c) 50 Amps, 80,000 Volts d) 0.5 Amps, 8000 Volts

b) 0.5 Amps, 80,000 Volts

If the total resistance in a circuit is 9 ohms and the total voltage is 3 volts, the current is a) 1/27 ampere. b) 1/3 ampere. c) 3 amperes. d) 27 amperes.

b) 1/3 ampere

What is the total resistance of a circuit if it contains resistances of 3 Ohms, 2 Ohms, and 10 Ohms in series? a) 1.07 Ohms b) 15 Ohms

b) 15 Ohms

If 10 coulombs pass a point in 2 seconds, the current is a) 0.20 amp. b) 5 amps. c) 20 amps. d) 200 amps.

b) 5 amps

What changes AC to DC? a) Step-down transformer b) Rectifier c) Cathode d) Timer

b) Rectifier

When an electric current flows through a wire with resistance, energy is a) liberated as x-rays. b) liberated as heat. c) liberated as light. d) absorbed as heat.

b) liberated as heat

resistance depends on all of these EXCEPT a) length b) material c) diameter d) temperature e) material conductivity

b) material

If 20 volts of potential difference causes a current of 5 amperes, the resistance produced is a) 1/100 ohm. b) 1/4 ohm. c) 4 ohms. d) 100 ohms.

c) 4 ohms

Current is a) time/charge. b) charge/time. c) (charge)(time). d) charge/time2.

c) charge/time

A step-up transformer a) increases energy b) decreases energy c) increases voltage d) decreases voltage

c) increases voltage

Electric insulators a) convert electrical energy into heat. b) consist of materials like silicon. c) inhibit movement of electrical charge. d) permit movement of electrical charge.

c) inhibit movement of electrical charge

The autotransformer a) lowers voltage b) increases voltage c) makes voltage constant d) changes current from DC to AC

c) makes voltage constant

What is current? a) mAs b) mass c) the number of electrons flowing past a point per second d) sine waves

c) the number of electrons flowing past a point per second

Electric potential is measured in a) coulombs. b) joules. c) volts. d) ohms.

c) volts

A current of 2 amperes and a resistance of 8 ohms require what voltage in a circuit? a) 1/16 volt b) 1/4 volt c) 4 volts d) 16 volts

d) 16 volts

Potential difference a) is the force that drives electrons b) measured in volts c) the larger the difference the larger the flow d) all of the above

d) all of the above

a step down transformer a) increases energy b) decreases energy c) increases voltage d) decreases voltage

d) decreases voltage

A volt is a measure of a) random drift velocity. b) flow rate. c) current. d) potential difference.

d) potential difference

The unit of electrical power is a) joule. b) volt. c) ampere. d) watt.

d) watt

As diameter increases, resistance ______. This is a ______ relationship.

decreases, inverse

Rotaring activates the _________.

filament circuit

The secondary side has _____ voltage

high

As temperature increases, resistance _____. This is a _____ relationship.

increases, direct

as length increases, resistance ______. This is a ______ relationship

increases, direct

The filament circuit has _____ voltage

low

The primary side has _____ voltage

low

resistance is measured in

ohms

Where is the mA selector

rheostat