The indirect operation of solenoid valve in pneumatic circuit is designed to reduce

1. Valve size towards lowering the cost

2. Coil size and electrical power consumption

3. Response time

Which of the above is/are relevant to the context?

The indirect operation of a solenoid valve in a pneumatic circuit can reduce the response time of the valve. This is because the solenoid valve is operated by an electric signal that controls the flow of compressed air to the valve, allowing it to open or close quickly.

Here, Option 1 (reducing valve size) and Option 2 (reducing coil size and electrical power consumption) are not directly related to the indirect operation of a solenoid valve. However, they can be important considerations in the overall design and selection of components for a pneumatic circuit.

Reducing valve size can help lower costs and save space, while reducing coil size and electrical power consumption can help improve energy efficiency and reduce operating costs. But these factors may not be directly related to the use of indirect operation of a solenoid valve.

Hence, the correct answer is option 3.