Physical Science

posted by on .

I am working on PS and I have a couple of questions.

1) If 24 amperes of current flows through an appliance connected to a 120-volt circuit what is the resistance of the appliance.

A).22 ohms
b)5 ohms
c)50 ohms
d)2880 ohms

I am not sure how to go about figuring that one out

2)If you doubled both the voltage and the resistence in a circuit what would be the effect on the current?

a)the current would increase by 4 times

b)the current would be doubled

c)the current would stay the same

d)the current would decrease 1/4

I think the answer is C

3)when there is a change in the magnetic field in a closed loop of wire.

a)electromagnetic induction occurs

b)a voltage is induced in the wire

c)current is made to flow in the loop of wire.

d)all of the above

I think is is A or possibly D

4)power is transmitted at high voltages because the corresponding current in the wires is?

a)also high to deliver appreciable power to distant places

b)low so that overheating of the wires is minimized.

c)both a and b

d)neither a nor b

I think it is A

5)when a magnet is pushed back and forth 1 time per second through a coil of wire made of 10 loops it produces 10 amperes of current. If we want to make it produce 100 amperes what should we do?

a)move the magnet back and forth more slowly about once every 10 seconds

b)increase the number of loops to 100 and push at the same rate

c)decrease the number of loops to only one loop and move at the same rate

d)decrease the coils to 5 coils and inscrease the motion to twice as fast.

I really have no idea on this one, and can't find anything about it in the book or online.

Thanks so much for the help

R=V/I.

So #1 is B 5?

5. Magnetic induction is proprotional to number of turns, and frequency.
4. Nonsense. Power= V*I
3. It is not A or D, it is one of them.
2. correct.

If R=V/I,then 120V/24A=?It does not get much easier!Try a calculator.