Suppose that the lab wiring is mistakenly designed so that all the stations are on the same 120Volt circuit. A circuit breaker allows a maximum of 40Amps to be drawn by the lab stations. If each lab station used 550watts or power how many lab stations can be running at once before the circuit breaker cuts off the power

9 stations .

Explanation:

All the stations are connected in parallel .

volt at each station =  120 V .

power used at each stations = 550

power = volt x current

550 = 120 x current

current = 4.5833 A

maximum current allowed by circuit breaker = 40 A

no of lab stations possible = 40 / 4.5833

= 8.72 or 9 .

the part of the wave he is travelling on is the crest

iron would move it is magnetic there is a mag field around the current in the wire