Basic Electricity Quiz

What is the symbol for electric charge?

• I

• C

• Q

• E

Answer explanation

The symbol for electric charge is 'Q'. It is commonly used in physics to represent electric charge, distinguishing it from other symbols like 'I' for current, 'C' for capacitance, and 'E' for electric field.

Which of the following materials is a good conductor?

• Plastic

• Copper

• Glass

• Rubber

Answer explanation

Copper is a good conductor of electricity due to its high electron mobility, allowing it to easily transfer electrical current. In contrast, plastic, glass, and rubber are insulators and do not conduct electricity well.

What is the practical unit of resistance?

• Ohm

• Volt

• Ampere

• Coulomb

Answer explanation

The practical unit of resistance is the Ohm, which measures how much a material opposes the flow of electric current. The other options, Volt, Ampere, and Coulomb, refer to voltage, current, and charge, respectively.

What does AC stand for?

• Alternating Current

• Active Current

• Ampere Current

• Analog Current

Answer explanation

AC stands for Alternating Current, which is a type of electrical current that reverses direction periodically, unlike the other options which are not standard terms in electrical engineering.

What is the relationship expressed by Ohm's Law?

• I = E/R

• E = I/R

• R = E/I

• I = R/E

Answer explanation

Ohm's Law states that current (I) is equal to voltage (E) divided by resistance (R). Therefore, the correct relationship is I = E/R, indicating how these three electrical quantities are interrelated.

Which of the following is a characteristic of DC?

• Varying magnitude

• Fixed polarity

• Reverses polarity

• Alternates direction

Answer explanation

DC (Direct Current) is characterized by a constant flow of electric charge in one direction, which means it has a fixed polarity. This distinguishes it from AC (Alternating Current), which varies and alternates direction.

What is the unit of electrical power?

• Ampere

• Volt

• Watt

• Joule

Answer explanation

The unit of electrical power is the Watt. It measures the rate at which electrical energy is transferred. Other options like Ampere and Volt measure current and voltage, respectively, while Joule measures energy.

What is the purpose of insulators?

• To store charges

• To allow current to flow

• To increase resistance

• To prevent the flow of electricity

Answer explanation

Insulators are materials that prevent the flow of electricity by having high resistance. This property makes them essential for protecting against electrical currents and ensuring safety in electrical systems.

What is the practical unit of voltage?

• Ohm

• Volt

• Ampere

• Coulomb

Answer explanation

The practical unit of voltage is the Volt. It measures the electric potential difference between two points. Ohm refers to resistance, Ampere to current, and Coulomb to charge, making Volt the correct choice.

Which of the following is a semi-conductor material?

• Aluminum

• Rubber

• Copper

• Silicon

Answer explanation

Silicon is a well-known semiconductor material, widely used in electronics. Unlike metals like aluminum and copper, which are good conductors, or rubber, which is an insulator, silicon has properties that allow it to conduct electricity under certain conditions.