Electricity and Circuits Quiz

What does the equation V = IR represent in the context of electricity?

• Voltage equals resistance times power

• Voltage equals current times resistance

• Resistance equals voltage times current

• Current equals voltage times resistance

If a circuit has a current of 4 amps and a resistance of 2 ohms, what is the voltage?

• 2 volts

• 6 volts

• 8 volts

• 10 volts

How do you calculate resistance if you have the voltage and current?

• R = V * I

• R = V / I

• R = V + I

• R = I / V

What happens to the current if the voltage increases while the resistance remains constant?

• The current fluctuates

• The current decreases

• The current remains the same

• The current increases proportionally

In a V-I graph, what does a straight line indicate about the resistance?

• The resistance is infinite

• The resistance is zero

• The resistance is constant

• The resistance is changing

How does a larger resistor affect the slope of the V-I graph?

• It makes the slope zero

• It does not affect the slope

• It makes the slope less steep

• It makes the slope steeper

What assumption is made about temperature in the V-I graph for wires and resistors?

• Temperature increases

• Temperature stays constant

• Temperature decreases

• Temperature fluctuates

What happens to the resistance of a filament lamp as the current increases?

• Resistance increases

• Resistance fluctuates

• Resistance stays the same

• Resistance decreases

Why do diodes only show current when the potential difference is positive?

• They have high resistance in the reverse direction

• They have low resistance in the reverse direction

• They have fluctuating resistance

• They have no resistance in any direction

What is the main function of a diode in a circuit?

• To block current flow completely

• To allow current to flow in both directions

• To increase the current flow

• To allow current to flow in one direction only