help

[pompeychris]

HI there doing a new careers course on being a domestic electrical installer and got stuck on a question so wondering if any of you guys could give me a hand?

Which of the following is not an advantage of using a MCB instead of a rewirable fuse?

a)Visual indication of failure

b)Rapid reseting of the device

c)can be locked for isolation

d)needs an electrican to reset

any ideas help thanks

 

[Richard Burns]

what about this one, a relay coil induces a magnetic flux of 200u (wb) in its laminated core of 150mm squared, establish magnetic flux?????

If the coil induces a magnetic flux of 200 micro Wb then the magnetic flux is 200 micro Wb!
The magnetic flux density is 1.33T