P5.3 Electrical power and potential difference Flashcards
What is the formula for electrical power?
Power (P) is calculated using the formula P = VI, where V is the potential difference and I is the current.
True or False: Electrical power is measured in volts.
False. Electrical power is measured in watts.
Fill in the blank: The unit of potential difference is ______.
volts
What does the term ‘potential difference’ refer to?
Potential difference refers to the difference in electric potential between two points.
If the current flowing through a circuit is 2 amperes and the potential difference is 10 volts, what is the power?
The power is 20 watts.
Multiple Choice: Which of the following is a correct unit for measuring power? A) Amperes B) Volts C) Watts D) Ohms
C) Watts
What is the relationship between power, voltage, and resistance according to Ohm’s Law?
According to Ohm’s Law, power can also be calculated using P = V^2 / R.
True or False: Higher potential difference results in lower power consumption.
False. Higher potential difference generally results in higher power consumption.
Fill in the blank: The power dissipated in a resistor can be calculated using the formula P = ______.
I^2R
What is the significance of a voltmeter in an electrical circuit?
A voltmeter measures the potential difference between two points in a circuit.
What happens to the power if the current is doubled while the potential difference remains constant?
The power will double.
Multiple Choice: If the power is 50 watts and the potential difference is 5 volts, what is the current? A) 5 A B) 10 A C) 25 A D) 50 A
B) 10 A
Define the term ‘electric circuit.’
An electric circuit is a closed loop that allows current to flow from a power source to a load and back.
True or False: Potential difference can exist without current flowing in a circuit.
True.
What is the effect of increasing resistance on power in a constant voltage circuit?
Increasing resistance will decrease the current and thus decrease the power.
