Which one of the following is the purpose for providing lengthwise grooves on the adjustable cylindrical lap ?

19) Which among the following is the movement of the honing machine during operation

20) Which one of the following abrasives is used for honing non-ferrous metals ?

21) Which among the following abrasives is used for honing tungsten steel ?

22) Which one of the following abrasives is used for lapping gauges ?