Question 1:What is the principle of working of PSTN?Circuit SwitchingPacket SwitchingCircuit + Packet SwitcingNone of the above

The principle of working of PSTN (Public Switched Telephone Network) is Circuit Switching.

Here's a step-by-step explanation:

1. When a call is made from one telephone to another, PSTN establishes a dedicated circuit between the two telephones. This circuit remains open for the duration of the call, which is why it's called "circuit switching".

2. The circuit can be a physical path (like a wire) or a logical path through a digital network. The path is established using a series of switches, which are located in telephone exchanges.

3. The switches in the exchanges open and close to create a continuous circuit from the caller to the receiver. This circuit allows the voice data to travel from one end to the other.

4. Once the call is finished, the circuit is broken and the path is freed up for other calls.

So, the correct answer to the question is "Circuit Switching".

The principle of working of PSTN (Public Switched Telephone Network) is Circuit Switching.

Here's a step-by-step explanation:

1. When a call is made from one telephone to another, PSTN establishes a dedicated circuit between the two phones. This circuit remains open for the duration of the call.

2. The circuit provides a direct and constant connection between the caller and the receiver. This is why it's called "circuit switching" - because the circuit is "switched" to allow for a direct path between the two phones.

3. This method of communication ensures that the quality of the call is maintained, as the connection is not shared with any other calls or data.

4. Once the call is ended, the circuit is broken and the path is freed up for other calls.

So, the correct answer to the question is "Circuit Switching".