Parallel Circuit analysis MCQ Questions.

## Parallel Circuit analysis MCQ#1

Consider the circuit given below and then answer the questions provided below:

### Equivalent resistance Example

What is equivalent resistance of circuit:

- 2k ohm
- 6k ohm
- 10k ohm
- 15k ohm

Correct answer: 2. 6k ohm

*Req = 1/(1/R1 + 1/R2) = 1/(1/10 + 1/15) = 6k ohm*

Learn More examples on parallel circuits here

### Find current across R1

The current across resistor R1 is:

- 1 mA
- 2 mA
- 5 mA
- 10 mA

Correct answer: 2. 2 mA

You can use Ohm’s law: I =V/R = 20/10 kohm = 2 mA

OR alternatively you can use current divider rule

### Find current across R2

The current across resistor R2 is:

- 1.33 mA
- 5 mA
- 13.44 mA
- 25.8 mA

Correct answer: 1. 1.33 A

Solution: *From Ohm’s Law: I = V/R = 20/15k = 1.33 mA*

### Find total incoming current

What is value of It:

- 1.33 mA
- 2 mA
- 3.33 mA
- None of the above

Correct answer: 3. 3.33 mA

Solution: There are two methods that can be used

By directly Using Ohm’s law:

I = V/Req = 20 V/6k = 3.33 A

OR use Ohm’s law to find individual currents (as we did earlier) and then use Kirchoff’s current law to find equivalent resistance.

### Find power consumed by R1

What is total power consumed by R1:

- 10 mW
- 20 mW
- 30 mW
- 40 mW

Correct answer: 4. 40 mW

Formula:

P = V^{2}/R = (20)^{2}/10k = 400/10k = 40 mW

### Find power consumed by R2

What is total power consumed by R2:

- 6.66 mW
- 16.66 mW
- 26.66 mW
- 36.66 mW

Correct answer: 3. 26.66 mW

Formula:

P = V^{2}/R = (20)^{2}/15k = 400/15k = 26.66 mW

### Find power delivered by Voltage source

Find total power delivered by voltage source:

- 35 mW
- 60 mW
- 66.66 mW
- None of the above

Correct answer: 3. 66.66 mW

*Total power = Sum of powers dissipated = 40 + 26.66 = 66.66 mW*