## Parallel Networks MCQ (Interview-Exam) Question-Answer

**Q.1** Calculate the current across the 20 ohm resistor.

**A.** 20A

**B.** 36.67A

**C.** 10A

**D.** 6.67A

**Ans : **10A

**Explanation: ** I=V/R. Since in parallel circuit, voltage is same across all resistors. Hence across the 20 ohm resistor, V=200V so I=200/20=10A.

**Q.2** If two bulbs are connected in parallel and one bulb blows out, what happens to the other bulb?

**A.** The other bulb continues to glow with the same brightness

**B.** The other bulb stops glowing

**C.** The other bulb blows out as well

**D.** The other bulb glows with increased brightness

**Ans : **The other bulb continues to glow with the same brightness

**Q.3** The current in each branch of a parallel circuit is proportional to _________

**A.** Proportional to the value of the resistors

**B.** Proportional to the power in the circuit

**C.** The amount of time the circuit is on for

**D.** Equal in all branches

**Ans : **Proportional to the value of the resistors

**Q.4** In a parallel circuit, with a number of resistors, the voltage across each resistor is ________.

**A.** Is divided equally among all resistors

**B.** Is zero for all resistors

**C.** The same for all resistors

**D.** Is divided proportionally across all resistors

**Ans : **The same for all resistors

**Q.5** The voltage across the open circuit is?

**A.** Infinity

**B.** 0V

**C.** 100V

**D.** 90V

**Ans : **100V

**Explanation: ** The voltage across all branches in a parallel circuit is the same as that of the source voltage. Hence the voltage across the 10 ohm resistor and the open circuit is the same=100V.

**Q.6** Calculate the total current in the circuit.

**A.** 10 A

**B.** 15 A

**C.** 20 A

**D.** 11.43 A

**Ans : **11.43 A

**Explanation: ** The 1 ohm and 2 ohm resistor are in series which is in parallel to the 3 ohm resistor. The equivalent of these resistances (3/2 ohm) is in series with the 4 ohm and 5 ohm resistor. Total R = 21/2 ohm. I=V/R=120/(21/2)=240/21=11.43 A.

**Q.7** If the current through x ohm resistance in the circuit is 5A, find the value of x.

**A.** 5 ohm

**B.** 135 ohm

**C.** 27 ohm

**D.** 12 ohm

**Ans : **27 ohm

**Explanation: ** R=V/I. In this circuit I=5A and V=135V. Therefore, R=135/5=27 ohm.

**Q.8** The voltage across the short is?

**A.** Infinity

**B.** 11.25V

**C.** 135V

**D.** Zero

**Ans : **Zero

**Explanation: ** The voltage across a short is always equal to zero whether it is connected in series or parallel.

**Q.9** The total resistance between A and B are?

**A.** 5 ohm

**B.** 0 ohm

**C.** 20 ohm

**D.** 80 ohm

**Ans : **5 ohm

**Explanation: ** I=V/R. Total resistance R = 20+40=60ohm. V=120V. I=120/60=2A.

**Q.10** The currents in the three branches of a parallel circuit are 3A, 4A and 5A. What is the current leaving it?

**A.** Insufficient data provided

**B.** 12A

**C.** 0A

**D.** The largest one among the three values

**Ans : **12A

## Parallel Networks in Electrical Engineering

**1. Redundancy and Reliability:**

- One of the primary purposes of parallel networks is to enhance system reliability. If one path or component fails, the system can continue to operate using an alternative path.
- Redundancy in parallel networks helps in minimizing the impact of component failures, ensuring continuous operation and reducing downtime.

**2. Load Sharing and Balancing:**

- Parallel networks allow for load sharing among multiple paths or components. This helps in distributing the workload evenly, preventing overloading of any single element.
- Load balancing ensures optimal utilization of resources and improves the overall efficiency of the system.

**3. Performance Improvement:**

- Parallel networks can be used to enhance the performance of a system by allowing multiple operations to occur simultaneously.
- In data processing and communication systems, parallel processing can lead to faster data transmission and reduced latency.

**4. Scalability:**

- Parallel networks provide scalability by allowing the addition of more components or paths to handle increased loads or requirements.
- This scalability is beneficial in various applications, such as cloud computing and data centers.

**5. Fault Tolerance:**

- Parallel networks contribute to fault tolerance by providing alternative routes or components in case of faults or errors.
- This feature is crucial in critical systems where continuous operation is essential, such as in power distribution networks and mission-critical communication systems.

**6. Power Distribution Systems:**

- In power distribution systems, parallel networks are used to ensure reliable and continuous power supply. Multiple lines or circuits are employed to distribute electrical power to consumers.
- This configuration allows for rerouting power in case of faults or maintenance activities, minimizing disruptions.

**7. Communication Networks:**

- Telecommunication networks often employ parallel paths to ensure reliable and efficient data transmission. Multiple communication channels help in maintaining connectivity and preventing data loss.

**8. Computing Systems:**

- Parallel computing involves the simultaneous execution of multiple tasks to improve computational efficiency. Parallel networks in computing systems enable faster processing and better utilization of resources.

**9. Research and Development:**

- Parallel networks are extensively used in research and development, particularly in simulation and modeling tasks. Parallel processing accelerates complex calculations and simulations, saving time and resources.

**10. Cost Considerations:**

- While parallel networks offer numerous benefits, there are also cost considerations associated with the implementation of redundant components and infrastructure.
- Designing a cost-effective parallel network requires a balance between redundancy, reliability, and the overall cost of the system.