Electricity

Question 1

What is the general rule for voltage in a Series Circuit?

Answer 1

The voltage across each component in a series circuit add up to the supply voltage. So Vs=V1+V2+V3 …..

Question 2

What is the general rule for current in a Series circuit?

Answer 2

The current in a series circuit is the same in all positions in the circuit. So Is=I1=I2=I3 …

Question 3

What is the general rule for voltage in a parallel circuit?

Answer 3

The voltage in a parallel circuit is the same in all positions in the circuit. So Vs=V1=V2=….

Question 4

What is the general rule for current in a parallel circuit ?

Answer 4

The current at each component in a parallel circuit add up to the supply current. So Is=I1+I2+I3

Question 5

What is the formula for adding resistors in series?

Answer 5

RT=R1+R2+R3

- Total resistance is simply the resistors added together

Question 6

What is the formula for adding resistors in parallel?

Answer 6

• The total resistance of resistors in parallel is always smaller than the smallest resistor
  1/RT= 1/R1 + 1/R2 + …..
• As more resistors are added the total resistance is smaller

Question 7

What do LED’s always need?

Answer 7

They always need a protective resistor to limit current through LED.

Question 8

What way does current flow through LED’s?

Answer 8

Against the arrowhead

- If the circuit has the flow of current moving with the arrowhead the circuit is not complete and will not work

Question 9

Are LED’s a low or high current device?

Answer 9

LED’s are a low current device

- 10 to 20 mA is max current

Question 10

What are the power calculations?

Answer 10

P=E/t - > P=Power, E=Energy and t=time
P=IxV - > P=Power, I= Current, V=Voltage
P=I^2R - > P=power, I^2 = Current squared, R=resistance
P= V^2/R - > P=power,V=voltage, R=resistance