NIU ELE 100 Quiz 7

How do you find the total resistance in a parallel circuit?

Total resistance RT is the reciprocal of the sum of the reciprocal of all the individual resistances. 1/RT = 1/R1 + 1/R2 + 1/R3 +.......

A circuit has three 30 Ω resistors connected in parallel. What is the total equivalent resistance of the circuit?

10 Ω Solution: 1 / 30Ω + 1 / 30Ω + 1 / 30Ω = 0.033Ω + 0.033Ω + 0.033Ω = 0.099Ω 1 / 0.099Ω = 10Ω

If R1 is disconnected (or removed) from the circuit shown below, what would be the total resistance? R3 = 900 Ω - parallel R2 = 100 Ω - parallel R1 = 10 Ω - series

90 Ω Solution: 900Ω * 100Ω = 90,000Ω 900Ω + 100Ω = 1,000Ω 90,000Ω / 1000Ω = 90Ω

If R2 is disconnected (or removed) from the circuit shown below, what would be the total resistance? R3 = 900 Ω - parallel R2 = 100 Ω - parallel R1 = 10 Ω - series

910 Ω Solution: 900Ω + 10Ω = 910Ω

What makes a circuit a parallel circuit?

There is MORE than one path for the current to flow.

What are the readings on the ammeters (these are instruments to measure the current) A1 and A4 in the circuit shown below if A2 = A3 = 2 Ampere? A1 -> A4 A2 X A3 X

A1 = 4 Amperes & A4 = 4 Amperes

The voltage across any branch of a parallel circuit is_____________.

is the same as the other parallel elements

If the first resistor R1 in the circuit shown below opens up, what will the total current be? I2 = R2 = 128 mA I1 = R1 = 42 mA IT -> Vs

128mA Solution: R2 = 128mA

What is the total current in the circuit shown here? I2 = 128 mA I1 = 42 mA IT -> Vs

170mA Solution: 128mA + 42mA = 170mA

In the circuit shown above, apply Kirchoff's Current Law (KCL), and determine I2. I1 = 7 A ^ I3 = 4 A ^ I2 = ->

3 A

In a parallel circuit as shown below, if one of the bulb burns out what happens to the rest of the bulbs in the circuit?

will continue to glow