Unit 4: Lesson 1:Flow of Electrical Energy

If the potential difference across the bulb in a camping lantern is 9.0 V, what is the potential difference across the battery used to power it?

9.0

Which change can result from a current moving through a copper conductor?

an increase in temperature

What happens to a current when the electric field in the wire increases?

The drift velocity increases, and the number of electrons passing through a cross-section of wire increases.

What are two ways that resistance can be increased by changing a wire?

by increasing the wire’s length and decreasing the wire’s width

Why can the energy stored in a battery be considered electrical energy?

The energy gives rise to a potential difference.

An electrical circuit is made using copper wire. The circuit is rebuilt repeatedly using thinner copper wire each time. What happens to the electron flow in the circuit as the wire becomes thinner and thinner?

The electrons move less easily through the wire.

Which one describes the speed of an electron moving in an electric field in a conductor?

drift velocity

How would the current running through a resistor of 6.2 Ω change if the voltage increased by a factor of 3?

The current would increase by a factor of 3.

Which statement describes the movement of current and electrons in a wire?

Electric current runs from the positive to the negative terminal, and electrons move in the opposite direction.

One ampere of current is defined by the movement of which of these through a given area in one second?

one coulomb of charge

Explain how electrical energy is transferred in an electric heater. (P. 251)

Electrical energy is converted to thermal energy in the heating element due to resistance, and this thermal energy is then transferred to the surroundings via convection and radiation

A circuit is made of a battery, a light bulb, and a 2 Ω resistor. The battery has a voltage of 3 volts. When connected, the ammeter reads a current of 1 amp in the circuit. Find the resistance of the light bulb. (P. 250)

1 Ω

A complete circuit allows electric current to flow. (P. 244-245)

a) Describe how alternating current affects the movements of electrons in a circuit.

b) Describe an advantage of using direct current instead of alternating current for portable electronic devices.

a) Alternating current causes electrons in a circuit to periodically change direction, moving back and forth. This movement is called the electrical charge. That movement back and forth is what creates the current.

b)Direct current is advantageous for portable electronic devices because it provides a stable and constant voltage, which is essential for the reliable operation of electronic components.

Explain how conductors and insulators are different in terms of the movement of the outer electrons of their atoms. (P. 247)

Conductors have outer electrons that are loosely bound and can move freely between atoms, allowing for easy flow of electrical charge. Insulators, on the other hand, have outer electrons that are tightly bound to their atoms and cannot move freely, thus restricting the flow of electrical charge.

Explain how the presence of a potential difference in a wire results in the movement of electrons. (P. 243)

The presence of a potential difference in a wire creates an electric field that exerts a force on the electrons, causing them to move and creating an electric current