Ohm's law basics
what is the formula for ohms law
V=IxR
what is the voltage if current is 2A and resistance is 4
8v
What unit is used for voltage?
volts (V)
if a circuit has no resistance what happens to the current
it becomes very large
What household item uses resistance to produce heat?
a toaster or heater
in ohms law what does the V stand for
Voltage
What is the current if voltage is 12 V and resistance is 6
2A
What unit is used for current?
amperes (A)
In a series circuit, what happens to total resistance when you add a resistor?
it increases?
What is an example of a device that needs low resistance to work well?
a wire or power cord
what does the I represent
current
What is the resistance if voltage is 10 V and current is 5 A
2
What unit is used for resistance?
ohms (Ī©)
In a parallel circuit, what happens to total resistance as you add more branches
it decreases
Why are metals good conductors?
they have low resistance
what does the R represent
Resistance
If a circuit has 0.5 A of current and 100 of resistance, what is the voltage?
50V
What do you use to measure voltage in a circuit?
a voltmeter
A 9V battery is connected to a 3 resistor. What is the current?
3 A
Why do some phone chargers heat up when in use?
resistance causes heat
if voltage increases but resistance stays the same that happens to the current
it increases
If you double the resistance, what happens to current
it is halved
what does ohms law help with
calculating static electricity
A student measures 0.2 A of current and 5 V of potential difference. What is the resistance?
the answer is 25 resistance
What does a fuse do in a circuit?
it breaks the circuit if current is too high