निम्नलिखित में से कौन सा बॉयलर (boilers) के वर्गीकरण का एक मानक आधार नहीं है?

Which of the following boiler mountings is used for the periodical cleaning or discharging of water and mud/sediments from the bottom of a boiler?

Natural draught for exhaust flue gases is provided during the working of a steam generator by ________.

Which of the following statements is correct with respect to the Cochran boiler?

In which of the following types of draught is air forced into the boiler furnace under pressure by a fan?

Which of the following statements is/are correct regarding Fire Tube Boilers? 1) In fire tube boilers, the hot gases are inside the tubes and water surrounds the tubes. 2) Cochran boiler is a type of fire tube boiler. 3) Stirling boiler is a type of fire tube boiler.