Electric Current and Circuit Components Assessment

Why does conventional current flow in the opposite direction of electron flow?

• Because electrons are positively charged
• Because conventional current assumes positive charge movement while electrons are negative
• Because batteries push electrons in reverse
• Because current always flows opposite to electrons

A current of 2 amperes flows through a circuit for 3 seconds. How many coulombs of charge have passed through?

• 1 coulomb
• 2 coulombs
• 6 coulombs
• 5 coulombs

Why do ammeters have very low resistance?

• To save energy
• To avoid affecting the current they're measuring
• To prevent overheating
• To make them cheaper to manufacture

If the voltage across a component is 12V and the current flowing is 2A, what is its resistance?

• 6Ω
• 10Ω
• 14Ω
• 24Ω

Which of these would increase the resistance of a metal wire?

• Increasing its cross-sectional area
• Decreasing its length
• Increasing its temperature
• Cooling it down

What is the main difference between EMF and potential difference?

• EMF is energy gained by charges, PD is energy lost
• EMF is measured in volts, PD in amperes
• EMF only occurs in batteries, PD only in wires
• There is no difference

Why are voltmeters connected in parallel?

• To measure current accurately
• To avoid affecting the voltage being measured
• Because it's easier to install
• To protect the circuit

If you double the length of a wire, what happens to its resistance?

• It doubles
• It halves
• It stays the same
• It quarters

What is the purpose of a rheostat in a circuit?

• To measure current
• To store energy
• To vary the current flow
• To protect from overload

Which would make a better conductor?

• A thick iron wire
• A thin copper wire
• A thick copper wire
• A thin iron wire