Circuits
Voltage & Current
Ohm's Law
Everyday Electricity
Basic Knowledge
100
What type of circuit has only one path for the current to flow?
Series Circuit
100
What is the unit of electric current?
Ampere (A)
100
What is the formula for Ohm’s Law?
V = IR
100
What is the name of the device that supplies electrical energy in a circuit?
Battery
100
True or False — Rubber is a conductor.
False
200
What happens to the other bulbs in a series circuit if one bulb burns out?
All the bulbs go out, the circuit is broken.
200
What is the unit of electric potential difference (voltage)?
Volt (V)
200
A circuit has a voltage of 12V and resistance of 4Ω. What is the current?
I = V/R
12V ÷ 4Ω = 3A
200
What are two materials that are good conductors?
Copper, aluminum (any metal)
200
What are the 4 Basic Components of a circuit?
Battery (Power Source), A Conductor (Wire), A load (Lightbulb), and a Switch (Sometimes)
300
What type of circuit allows current to flow through multiple branches at once?
Parallel Circuit
300
What is the energy released from a battery in a lightbulb that was switched on for 45s, in which the voltage drop was 60V, and the current flowing was 0.35A?
P = I * V
P = 21 W
E = P * t
E = 945 J
300
What is the resistance if the voltage is 18V and the current is 6A?
R = V/I
18V ÷ 6A = 3Ω
300
What happens to the total current in a parallel circuit as more branches are added?
The total current increases
300
What is the Law of Attraction?
Law of attraction states that same charges repel, while opposite charges attract
400
0V, because the switch is open. If it was closed each bulb would have 3V.
400
What tool is used to measure voltage and how must it be connected in a circuit?
Voltmeter, connected in parallel
400
If a device uses 8A of current and 10V of voltage, what is its power?
P = IV
P = 8A × 10V = 80W
400
What does resistance do in a circuit?
It slows down the flow of electrons
400
To charge an electroscope with a Negative charge, you must touch it with a _______ charged object.
Negativley Charged Object
500
Imagine a Parallel Circuit with a 9V battery and 2 identical bulbs on separate branches. What is the voltage across each bulb?
9V, voltage is the same across each branch in a parallel circuit.
500
Two light bulbs are connected in Parallel. If one light bulb is burnt/unscrewed, the second light bulb will _____?
Remain Lit! ** Bonus: What happens if you add a third light bulb in parallel?
500
A 120V light bulb has a resistance of 30Ω. What is the power?
I = V/R
120 ÷ 30 = 4A
P = VI = 120 × 4 = 480W
500
What is the cost of using a refrigerator continuously for one day if it is rated at 1000W and the cost of electricity is $0.06/kWh?
E = P(kWh) * t (hours )
E = 24kWh
C = E * Cost per kWh
C = $1.44 or 144¢
500
True or False — Current in a series circuit splits equally between all paths.
False, Only Parallel