Understanding Electric Circuits

What is the flow of electricity in a circuit called?

• Capacitance

• Resistance

• Voltage

• Current

Answer explanation

The flow of electricity in a circuit is called 'current'. It represents the movement of electric charge, distinguishing it from capacitance (storage), resistance (opposition), and voltage (potential difference).

What are the charged particles that flow to create electric current?

• Electrons and ions

• Neurons and molecules

• Protons and neutrons

• Photons and positrons

Answer explanation

Electric current is created by the flow of charged particles. Electrons, which are negatively charged, and ions, which can be positively or negatively charged, are the primary carriers of electric current.

How do you represent a circuit diagram?

• A circuit diagram is drawn using freehand sketches without any standardization.

• A circuit diagram is represented using only colors and shapes without symbols.

• A circuit diagram is represented by writing out the components in a list format.

• A circuit diagram is represented using standardized symbols for components and connecting lines to show electrical connections.

Answer explanation

A circuit diagram uses standardized symbols to represent components and connecting lines to illustrate electrical connections, ensuring clarity and consistency in communication.

What is the circuit symbol for a cell?

• A single straight line.

• Two circles, one inside the other.

• A zigzag line with three peaks.

• Two parallel lines, one longer than the other.

Answer explanation

The circuit symbol for a cell is represented by two parallel lines, one longer than the other. The longer line indicates the positive terminal, while the shorter line represents the negative terminal.

What is the circuit symbol for a switch?

• A break in a line with a pivoting line connecting the two ends.

• A zigzag line with no connections.

• Two parallel lines with a diagonal line crossing them.

• A solid line with a circle at one end.

Answer explanation

The correct circuit symbol for a switch is represented as a break in a line with a pivoting line connecting the two ends, indicating the open and closed positions of the switch.

What unit is used to measure electric current?

• amperes

• watts

• ohms

• volts

Answer explanation

Electric current is measured in amperes, which quantify the flow of electric charge. Watts measure power, ohms measure resistance, and volts measure electric potential, making amperes the correct unit for current.

How can you measure the current in a circuit?

• Connect an ammeter in series with the circuit.

• Use a multimeter set to measure resistance.

• Disconnect the circuit to measure the current.

• Connect a voltmeter in parallel with the circuit.

Answer explanation

To measure current in a circuit, you must connect an ammeter in series. This allows the ammeter to measure the flow of electric charge directly, unlike a voltmeter or resistance measurement, which do not provide current readings.

What happens to current in a series circuit?

• The current varies at different points in a series circuit.

• The current is zero at all points in a series circuit.

• The current is the same at all points in a series circuit.

• The current is higher at the beginning of the circuit than at the end.

Answer explanation

In a series circuit, the current remains constant throughout all points. This means that the same amount of current flows through each component, making the correct answer "The current is the same at all points in a series circuit."

What is the difference between a conductor and an insulator?

• Insulators allow current to flow; conductors resist current flow.

• Conductors allow current to flow; insulators resist current flow.

• Conductors are always made of metal; insulators are always made of plastic.

• Conductors and insulators have the same electrical properties.

Answer explanation

Conductors allow current to flow easily due to their free electrons, while insulators resist current flow by preventing electron movement. This distinction is crucial in understanding electrical properties.

Can you name some common conductors?

• Rubber

• Wood

• Copper, Aluminum, Silver, Gold

• Plastic

Answer explanation

Common conductors include metals that allow electricity to flow easily. Copper, Aluminum, Silver, and Gold are well-known conductors, while Rubber, Wood, and Plastic are insulators that do not conduct electricity.