Electricity Flashcards
What is the unit of electric current?
Ampere (A)
True or False: Voltage is the measure of the energy per unit charge.
True
Fill in the blank: The formula for calculating resistance is ____ = Voltage / Current.
Resistance
What does Ohm’s Law state?
V = IR (Voltage = Current × Resistance)
What is the unit of electric charge?
Coulomb (C)
Multiple Choice: Which of the following is a conductor? A) Wood B) Copper C) Plastic D) Rubber
B) Copper
What is the formula for electric power?
P = IV (Power = Current × Voltage)
True or False: A series circuit has the same current flowing through all components.
True
What is the total resistance in a series circuit with three resistors of values R1, R2, and R3?
R_total = R1 + R2 + R3
In a parallel circuit, how is the total current related to the individual currents?
The total current is the sum of the individual currents.
What is the function of a fuse in an electrical circuit?
To protect the circuit by breaking the connection if the current exceeds a certain level.
Multiple Choice: Which law relates the voltage, current, and resistance in an electrical circuit? A) Newton’s Law B) Ohm’s Law C) Kirchhoff’s Law D) Faraday’s Law
B) Ohm’s Law
What is the principle of conservation of charge?
The total electric charge in an isolated system remains constant.
Fill in the blank: The energy transferred by an electric current is measured in _____.
Joules (J)
What is the difference between alternating current (AC) and direct current (DC)?
AC changes direction periodically, while DC flows in one direction.
True or False: A voltmeter is connected in series with the component to measure voltage.
False
What does a capacitor do in a circuit?
Stores electrical energy temporarily.
Multiple Choice: Which component is used to limit the current in a circuit? A) Capacitor B) Resistor C) Inductor D) Diode
B) Resistor
What is the formula for total resistance in a parallel circuit with two resistors, R1 and R2?
1/R_total = 1/R1 + 1/R2
True or False: The voltage across each component in a parallel circuit is the same.
True
What is Kirchhoff’s first law?
The total current entering a junction equals the total current leaving the junction.
Fill in the blank: The power dissipated in a resistor can be calculated using the formula P = ____ × R.
I² (Power = Current squared × Resistance)
What does the term ‘electrical efficiency’ refer to?
The ratio of useful power output to total power input.
Multiple Choice: What is the primary function of a transformer? A) Convert AC to DC B) Increase or decrease voltage C) Store energy D) Measure current
B) Increase or decrease voltage
What happens to the resistance of a conductor as its temperature increases?
The resistance typically increases.
True or False: Insulators allow electric current to flow freely.
False
What is the purpose of grounding in electrical systems?
To provide a safe path for excess current to flow to the earth.
Kirchoff’s first law?
The total current entering a junction is equal to the total current leaving the junction
Kirchoff’s second law.
For a complete circuit loop the sum of e.m.f. is equal to the p.d.s around the loop
How to add resistors in parallel?
Total resistance is the reciprocal of the resistance
1/r + 1/r + 1/r = 1/tr
R + R + R = tR
Equation for resistance in series
Two cells are pointed away from each other how to find voltage?
Take away larger v from smaller
