Ch8
What is the symbol for charge?
Q
How many laws does Kirchoff have?
2
What is the unit for resistance?
Ohms
What is the purpose of a thermistor?
To regulate the flow of current in a system based on temperature
What is defined as charge (C) divided by time (s)
Current
What is the unit for current?
Amps (A)
What is the other name of Kirchoff’s First Law?
The junction rule
In an I-V graph, which variable goes with what axis?
voltage goes in X-axis while Current goes in Y-axis
How does a thermistor work?
The resistance lowers as temperature rises
What is voltage?
The potential difference between two points in a circuit
What is the charge for an electron?
1.6x10^-19C
What is the junction rule?
The current going in is equal to the current going out
How do you find the resistance in a parallel?
1/R1 = Sum 1/R
How does an LDR work?
When there is light, the resistance decreases, and when there is no light, the resistance increases
What is the relationship between resistance and temperature in a thermistor?
They are inversely proportional, and one rises the other one lowers
What is resistance and how do you find it?
Resistance is the ratio of potential difference (voltage) across a circuit to the current flowing through it. It found using voltage divided current
How do you calculate Kirchoff’s second law?
The sum of all EMF is equal to the sum of potential difference
How do you find the EMF?
(Current x Internal R) + (Current x External R)
What is an example of a thermistor and an example of an LDR?
Thermistor: A/C unit
LDR: A desk lamp
What is defined as the rate at which work is done or energy transferred over time?
Power
If voltage is 10 and resistance is 8, what is the power in the system?
12.5 W
If a circuit has 5a entering, 4a leaving, 12a entering and another 4a leaving, what is the magnitude and direction of the next amp?
9 amps leaving
What is the internal resistance if the voltage is 60V and the current is 8A with an external resistance of 5Ω?
2.5Ω
A closed circuit is connected to a 100v battery, with an internal resistance of 2Ω, and 2 LDR’s connected in parallel, what is the current on each LDR if LDR 1 is 3Ω and LDR 2 is 5Ω?
I1 = 16.1a
I2 = 9.68a
What is the difference between series and parallel?
In a series -current remains the same while voltage changes
parallel - current changes and voltage stays the same