Which of the following is zero? (a) grad div (b) div grad Given field A- (a) Harmonic (b) Divergenceless (c) Solenoidal (c) curl grad (d) curl curl 3xyza, + x'za, + (x'y 22)a,, it can be said that A is (d) Rotational (e) Conservative If a vector field Q is solenoidal, which of these is true? (a) Q-dl-0 (b) fsQ.ds=0 (c) VXQ=0 (d) VXQ+0 (e) V²Q=0 Stokes's theorem is applicable only when a closed path exists and the vector field and its derivatives are continuous within the path. (a) True (b) False (c) Not necessarily mpo-