Grade 7 Science Electricity Quiz

What is an electric current?

• Flow of protons in a circuit

• Flow of neutrons in a circuit

• Flow of electrons in a circuit

• Flow of atoms in a circuit

Answer explanation

An electric current is defined as the flow of electrons in a circuit. Electrons are negatively charged particles that move through conductors, creating an electric current, unlike protons or neutrons which do not flow in this manner.

A battery consists of:

• A single cell

• Two or more cells joined together

• A wire and a lamp

• Only one positive terminal

Answer explanation

A battery is defined as two or more cells joined together, which work in unison to provide electrical energy. A single cell cannot be classified as a battery, making 'two or more cells joined together' the correct choice.

What is required for electricity to flow?

• An open circuit

• A closed circuit with no gaps

• A switch in the open position

• A single wire

Answer explanation

For electricity to flow, a closed circuit with no gaps is required. This allows the current to travel continuously. An open circuit, a switch in the open position, or a single wire cannot complete the circuit.

Electrons move from:

• Positive to negative terminal

• Negative to positive terminal

• The center to the outer edge

• Neutral to negative terminal

Answer explanation

Electrons are negatively charged and move from the negative terminal to the positive terminal in a circuit. This flow is opposite to the conventional current direction, which is from positive to negative.

Which of the following best describes electric current?

• It moves in the same direction as electron flow

• It moves in the opposite direction of electron flow

• It does not flow in a circuit

• It moves from neutral to charged areas

Answer explanation

Electric current is defined as the flow of electric charge. Since electrons carry a negative charge and flow from negative to positive, the conventional current is considered to move in the opposite direction of electron flow.

If a circuit is broken:

• The current keeps flowing

• The electrons move faster

• The current stops

• The battery produces more energy

Answer explanation

When a circuit is broken, the path for current flow is interrupted, causing the current to stop. Therefore, the correct answer is that the current stops.

Why do we use circuit diagrams?

• They are easier to draw

• They help avoid confusion with standard symbols

• They represent the same setup as the physical circuit

• All of the above

Answer explanation

Circuit diagrams are useful because they simplify the drawing process, utilize standard symbols to reduce confusion, and accurately represent the physical circuit setup. Therefore, all the provided reasons are valid.

What is the purpose of a switch in a circuit?

• To provide electrical energy

• To store electrical energy

• To start or stop the flow of current

• To measure current

Answer explanation

A switch is used to start or stop the flow of current in a circuit. It acts as a control mechanism, allowing users to open or close the circuit, thus enabling or disabling the electrical flow.

Which device is used to measure electric current?

• Voltmeter

• Ammeter

• Buzzer

• Transformer

Answer explanation

An ammeter is specifically designed to measure electric current in a circuit, while a voltmeter measures voltage, a buzzer produces sound, and a transformer changes voltage levels.

How should an ammeter be connected in a circuit?

• In parallel

• In series

• Randomly placed anywhere

• Across a resistor

Answer explanation

An ammeter must be connected in series with the circuit to measure the current flowing through it. Connecting it in parallel or randomly would not provide an accurate measurement and could damage the ammeter.