Lesson 11: Understanding Resistance in DC Parallel Circuits

Determine the value of R2 in the circuit.

100 Ω

What is the total circuit resistance with all switches closed? (Round the FINAL answer to two decimal places.)

134.33 Ω

What is the total circuit resistance with S1 and S3 closed? (Round the FINAL answer to two decimal places.)

171.49 Ω

What is the total circuit resistance with S1 and S2 closed? (Round the FINAL answer to two decimal places.)

188.09 Ω

Solve for total circuit resistance in the circuit. (Round the FINAL answer to two decimal places.)

2.22 Ω

Using the product over sum method, calculate the total resistance of a circuit with a 5-ohm, 10-ohm, and 15-ohm resistor in parallel.

2.73 Ω

What is the total resistance of the circuit with S1 closed, and both S2 and S3 open?

270 Ω

A circuit contains five 180-ohm resistors in parallel. What is the total circuit resistance? (Use the rule for determining total resistance with resistances of equal value.)

36 Ω

Solve for total circuit resistance in the circuit. (Round the FINAL answer to two decimal places.)

46.15 Ω

Determine the value of R3 in the circuit. (Round the FINAL answer to two decimal places.)

4714.29 Ω

Two lamps are connected in parallel across a 120-volt source. Each lamp has an internal resistance of 96 ohms. What is the equivalent circuit resistance?

48 Ω

Use a variation of the equal-resistance rule to solve for the equivalent resistance in the circuit. (Round the FINAL answer to one decimal place.)

7.2 Ω

Use the product-sum method to solve for total resistance in a circuit containing one 25-ohm and one 15-ohm resistor. (Round the FINAL answer to three decimal places.)

9.375 Ω

Adding additional resistors in parallel with those resistors already existing in a parallel connected circuit will always increase the total resistance.

False

When resistors are connected in parallel, the total resistance of the circuit will be greater than the smallest resistor value in the circuit.

False

State the product over sum formula for determining total resistance in parallel circuits containing two unequal resistances.

RT = R1 x R2 / R1 + R2

When can the reciprocal method be used to calculate total resistance in parallel circuits?

The reciprocal method can be used to calculate the total resistance of any combination of parallel resistances.

The total resistance of any number of parallel resistances, all having the same value, is equal to the value of any one of the resistors divided by the total number of resistors.

True

With S1 open, what affect will it have on the circuit?

With S1 open, the source is disconnected from the resistors since S1 open is in series with the source; therefore, no current would flow.