Misrun is a casting defect which occurs due to

Gray cast iron blocks $$200 \times 100 \times 10\,\,mm$$ are to be cast in sand moulds. Shrinkage allowance for pattern making is $$1$$%. The ratio of the volume of pattern to that of the casting will be

In a rolling process, sheet of $$25$$ $$mm$$ thickness is rolled to $$20$$ $$mm$$ thickness. Roll is of diameter $$600$$ $$mm$$ and it rotates at $$100$$ $$rpm.$$ The roll strip contact length will be

Two 1 mm thick steel sheets are to be spot welded at a current of $$5000$$ $$A.$$ Assuming effective resistance to be $$200$$ micro-ohms and current flow time of $$0.2$$ second, heat generated during the process will be