amrix

In an IC 741 op amp what is the use of having pins 1(offset null) 5(offset null) and 8(strobe)........???????

one of the following is not a source of magneto static fields: a.a dc current in a wire b.a charged disk rotating at uniform speed c.an accelerated charge since i don't have a clear idea of what an accelerated charge is i am confused what the answer might be......it would be kind of some one could help me out with it, in explaining what an accelerated charge is????