Principles of electricity

What are protons and neutrons tightly packed in?

• Nucleus

• Electron cloud

• Atomic shell

• Molecular bond

Answer explanation

Protons and neutrons are tightly packed in the nucleus of an atom. The nucleus is the central part of the atom, containing these particles, while the electron cloud surrounds it.

Which type of particle carries a negative charge?

• Proton

• Neutron

• Electron

• Positron

Answer explanation

The electron is the particle that carries a negative charge. Protons have a positive charge, neutrons are neutral, and positrons are the antimatter counterparts of electrons with a positive charge.

Oppositely charged particles interact with each other by:

• repelling each other

• attracting each other

• having no interaction

• forming a new particle

Answer explanation

Oppositely charged particles attract each other due to the electromagnetic force. This attraction is fundamental in physics, leading to the formation of stable structures like atoms.

What is the difference in electrical potential between two points called?

• Voltage

• Current

• Resistance

• Capacitance

Answer explanation

The difference in electrical potential between two points is called voltage. It measures the potential energy per unit charge and is essential for understanding electrical circuits.

What unit is used to measure the difference in electrical potential between the anode and cathode of a battery?

• Volt

• Ampere

• Ohm

• Watt

Answer explanation

The difference in electrical potential between the anode and cathode of a battery is measured in volts. This unit quantifies the electric potential energy per unit charge, making 'Volt' the correct choice.

What is the primary function of a resistor in an electrical circuit?

• To convert AC to DC

• To store energy

• To decrease current

• To increase voltage

Answer explanation

The primary function of a resistor is to decrease current in an electrical circuit. By providing resistance, it limits the flow of electric charge, ensuring that components receive the appropriate amount of current.

Which subatomic particle is found in the electron cloud surrounding the nucleus?

• Electron

• Quark

• Neutron

• Proton

Answer explanation

The electron is the subatomic particle located in the electron cloud that surrounds the nucleus of an atom. Quarks are found within protons and neutrons, while neutrons and protons reside in the nucleus itself.

What is the term for the flow of electric charge in a conductor?

• Current

• Resistance

• Voltage

• Capacitance

Answer explanation

The flow of electric charge in a conductor is called 'current'. It is measured in amperes and is essential for the operation of electrical devices.

What is the unit of electric current?

• Watt

• Ohm

• Volt

• Ampere

Answer explanation

The unit of electric current is the Ampere, often abbreviated as 'A'. It measures the flow of electric charge. Other options like Watt, Ohm, and Volt refer to power, resistance, and voltage, respectively.

What is the term for materials that do not allow electric charge to flow freely?

• Superconductors

• Semiconductors

• Insulators

• Conductors

Answer explanation

Insulators are materials that do not allow electric charge to flow freely, making them the correct choice. In contrast, conductors allow charge flow, while superconductors and semiconductors have specific conditions for conductivity.