Electrical parts
State the type of charge the following subatomic particles have:
protons, neutrons, electrons
+, no charge, -
What is the unit of electric current?
Amperes, A
State Ohm’s Law using the main formula.
V = IR
How many paths does current have in a series circuit?
1
What is the unit of electrical power?
watt, W
Why does a balloon stick to a wall after being rubbed on hair?
Because you build up excess negative charge on balloon and the balloon moves electrons in wall away exposing protons and they attract and stick.
What does voltage represent in a circuit?
Energy per unit charge / electrical potential difference
Rearrange Ohm’s Law to solve for resistance.
R = V/I
What stays the same across each branch of a parallel circuit?
Voltage
Write the formula for electrical power using voltage and current.
P = VI
What does "Charing by Induction" mean?
Charging an object without touching.
Why does increasing resistance decrease current?
Indirectly related / increasing resistance decreases the flow of electrons = reduced current
A circuit has 12.8 V and 350 mA. What is the resistance?
36.6 ohms
What happens to total resistance when more resistors are added in parallel?
Total resistance decreases
What is the purpose of a fuse in an electrical circuit?
To break the circuit and stop flow of electricity if system is overloaded.
What is the mass of an electron?
9.11 x10-31 kg
Why are electrons able to flow easily in metal wires?
wires are conductors
A resistor of 8 Ω has a voltage of 3.6 V. What is the current?
0.45 A
One bulb burns out in a series circuit. What happens to the others?
They all stop working
A device uses 600 W for 10 minutes. How much energy is used (in joules)?
360000 J
What is the name of the scientist that the charge is named after?
Charles Coulomb
What device measures current and voltage respectively?
Ammeter, voltmeter
Voltage doubles while resistance stays the same. What happens to current? Explain.
Current DOUBLES
Two resistors (4 Ω and 12 Ω) are in parallel with a 12 V source. Find total current.
4.0 A
Why are household circuits wired in parallel instead of series?
Devices recieve full voltage and work independently of each other.