A note about rms, which stands for root-mean-square: The rms voltage is a measure of the average effective voltage. If you use peak (maximum) values of voltage or current in any of the transformer equations, you get peak values out. If you use rms values in the equations, you get rms values out. The bottom line: Don't be confused by the rms values—you can use them in the equations and you'll be fine.

A typical pole-mounted transformer, the last step in the power distribution process before electricity is delivered to residential customers, has an rms voltage of 9600 volts on the primary coil. The secondary coil has an rms output voltage of 240 volts, which is delivered to one or more houses.

a. What is the ratio of the number of turns in the primary coil to the number in the secondary?
b. If the rms current on the primary side is 4.00 A, and each house requires an rms current of 40 A, how many houses can this transformer supply electricity to?

a. ratio = 40

b. 4 houses can be supplied

Explanation:

Relations in a Transformer

The pole-mounted transformers are mainly used to lower higher distribution voltages to residential-level voltages. It is done by using a combination of primary and secondary coils so the relation or ratio is correctly achieved.

a. The ratio between the number of turns in the primary coil to the secondary coil is

b. This ratio also applies to the primary and secondary currents, being the secondary current r times the primary current.

The ratio between the currents is given by

We can know the secondary current

Given each house requires 40 A rms, we can supply electricity to 160/40=4 houses

elly's long hair:

a. if the salon only takes cash, then this isn't the problem. it doesn't matter how much she has in her checking account.   she can't get a haircut until she has the cash.

b. if she has overdraft protection, then there's no problem.   she can go ahead and write a check that her account can't cover, then sometime later, pay the bank some outrageous usury for loaning her a few bucks for a few days, but with beautiful hair.

c. if elly has some principles, and doesn't want to write a bad check, then now she has a problem.   her desire for the new hairstyle is in conflict with her honesty and integrity.

d.   if the bank will not process a check she writes, then even if she had a million $$ in her account, she couldn't use any of it.   the amount she has in her account is not the problem.   and if i may suggest, she might as well close her checking account, and put the money where it'll work for her.   it's not doing her a bit of good in a checking account, since she can't write any checks.

justin can't pay the full balance:

a. he can't even handle the credit limit he has now.   under no circumstances should he ask for a higher limit.

b.   he can ask for the grace period to be extended.   but that's no solution, the bank will almost certainly refuse anyway, and there are much better options.   he knew the rules of his credit card when he started using it.

c.   he definitely should pay the interest on the balance, plus as much of the balance as he can cover at the same time.

d.   he definitely should pay the minimum otherwise they could shut down his card.   he should also pay as much more as he possibly can.   he should also remember the awkward situation he's in, stop buying stuff on credit that he can't afford, and avoid adding any more debt.

i'd say that justin's best best option isn't on this list of choices.   what he has to do:   pay as much as he can at least the minimum payment plus as much more as he can and then avoid adding more debt.