भारतीय मानकों के अनुसार, तृतीय श्रेणी (third-class) की ईंटों के लिए आवश्यक न्यूनतम संपीडन सामर्थ्य (compressive strength) कितनी होती है?

Which of the following artificial stones is produced by moulding a mixture of iron slag and Portland cement?

Enamel paint is generally prepared by adding:

Dorry's testing machine is used for which test on building stones?