Two examples for different electrical equipment’s which uses A. C supply and D. C supply

Ariver flows from north to south at 8 km/h. a boat is to cross this river from west to east at a speed of 20 km/h (speed of the boat with respect to the earth/ground). at what angle (in degrees) must the boat be pointed upstream such that it will proceed directly across the river (hint: find the speed of the boat with respect to water/river)? a 288 b. 21.8 c. 326 d. 30.2

The higher the astm grain size number, the finer the gran is. a)-true b)-false

The proportional limit is always greater than the yield strength for a material. a)-trune b)- false