Ohm's Law Check

Select all of the options that best complete the following sentence. 

In order to have a current flowing, a circuit must:

• be open

• be closed

• have a motor

• have an energy source

Select the option that best completes the following sentence. 

An electrical current in a metal wire is a flow of:

• volts

• atoms

• ohms

• electrons

The higher the voltage supplied to a circuit:

• the bigger the "push" received by electrons

• the lower the current

• the higher the resistance

• the less energy is used in a given time

When a charged battery is connected to a closed circuit, electrons flow from the ____________ terminal to the ____________ terminal.

• positive; negative

• negative; positive

• positive; positive

• negative; negative

Most electric heaters work by passing an electrical current through a component with very high resistance.

Select the option that best explains why resistance generates heat. 

• Resistance arises from the electrostatic repulsion between electrons and this generates heat

• Resistance arises from the collisions between flowing electrons and atoms; when electrons slow down their energy is converted into heat

• Resistance increases the current, causing electrons to flow more quickly and so with greater energy

• High resistance does not produce heat at all.

Recall which units are used to measure resistance. 

• Amperes

• Watts

• Volts

• Ohms

Select the option that best completes the following sentence. 

Adding resistance to a circuit will:

• do nothing

• increase the current

• increase the voltage

• decrease the current

Identify what the circuit symbols shown on the right are. 

• 1. battery, 2. lamp, 3. voltage, 4. open switch

• 1. open switch, 2. lamp, 3. resistor, 4. battery

• 1. battery, 2. lamp, 3. resistor, 4. open switch

• 1. lamp, 2. resistor, 3. battery, 4. closed switch

In the circuit diagram shown on the left, a 12 V battery is connected to a resistor and a motor (M). Determine how electrons will flow in this circuit. 

• From X to Y

• From Y to X

• Both from X to Y and from Y to X

• Not at all

Four circuits designed to operate a loudspeaker are shown on the right. Determine which circuit will make the loudspeaker work. 

• Circuit A

• Circuit B

• Circuit C

• Circuit D