Electricity Unit Review

3.10 - In an electrical circuit the charges must be introduced into the circuit and do not already exist within it.

• True
• False

3.10 - In a closed circuit an energy source does what?

• breaks and opens the circuit
• transfers energy to the already existing charges.
• acts as an insulator to hinder energy transfer
• creates energy

3.11 - This diagram shows what type of circuit?

• Circular
• Open
• Portioned
• Closed

3.11 - This image shows what kind of a circuit?

• Circular
• Closed
• Portioned
• Open

3.15 - When energy travels through a circuit to an electrical device ____________.

• an energy transformation takes place which can change the form of energy to light, heat, etc.
• Some of the energy is destroyed and that is why batteries die.
• the electrical device uses up the energy.
• that energy cannot be transformed.

3.15 - Which description below is best at explaining the energy transformations that take place when a light switch is turned on and lights come on in a room.

• Electromagnetic to chemical kinetic to thermal
• electrical potential to electrical kinetic to electromagnetic(light) and thermal(heat)
• electrical potential to electrical kinetic to sound and electrical potential
• chemical potential to electrical kinetic to light and kinetic

3.16 - Resistance can be described as ________.

• The rate or speed at which electrons are able to flow through a circuit or material.  Measured in amperes with an ammeter.  Can be thought of as how fast water is flowing in a river.  If there is a fast “current,” then there is lots of water moving past a location every second.  If there is a slow “current,” there is not much water moving past the location each second.
• A series of electrical devices linked together to form a chain that can be used to explain energy transformations.
• A measure of a material’s opposition to the flow of electrical current.  Measured in ohms (Ω) with an ohmmeter.  Can be thought of as how difficult it is for water to move down a river.  If there are lots of rocks or if the stream is very narrow, than the water will meet lots of resistance.  On the other hand, if the stream is wide and clear of debris, the water will flow quickly and without much resistance.
• The flow of electrons freely throught a circuit in which the energy transformations are contained in a directional pattern

3.16 - _____ is the rate or speed at which electrons are able to flow through a circuit. Measured in amperes with an ammeter.

• current
• resistance
• series
• parallel

3.16 - Which of the following shows the correct relationship between current and resistance?

• The lower the resistance the higher the current
• The higher the resistance the higher the current
• The higher the current the higher the resistance
• Current and resistance do not impact one another.

3.12 - Voltage is measured in ______ using a _______.

• Amps, Ammeter
• Ohms, Ammeter
• Volts, Voltmeter
• Ohms, Voltmeter