Question

Determine the amount
of current that flows with 250MC of charge in 10 minutes

Answer 1

Answer:

Electric current is defined to be the rate at which charge flows. A large current, such as that used to start a truck engine, moves a large amount of charge in a small time, whereas a small current, such as that used to operate a hand-held calculator, moves a small amount of charge over a long period of time. In equation form, electric current I is defined to be

I=

Δ

Q

Δ

t

I=Δ

Q

Δ

t,

where ΔQ is the amount of charge passing through a given area in time Δt. (As in previous chapters, initial time is often taken to be zero, in which case Δt = t.) (See Figure 1.) The SI unit for current is the ampere (A), named for the French physicist André-Marie Ampère (1775–1836). Since I = ΔQ/Δt, we see that an ampere is one coulomb per second:

1 A = 1 C/s

Not only are fuses and circuit breakers rated in amperes (or amps), so are many electrical appliances.