Rate in the Electrical System. 1. What is the prime mover in the electric system? - voltage 2. What...
-
Upload
stephany-maxwell -
Category
Documents
-
view
212 -
download
0
Transcript of Rate in the Electrical System. 1. What is the prime mover in the electric system? - voltage 2. What...
Rate in the Electrical System
Rate in the Electrical System1. What is the prime mover in the electric
system?- voltage
2. What is electric rate?- amount of charge that flows through a conductor in a unit of time
3. What term in given to electric rate?- current
Rate in the Electrical System
4. What letter is used to represent electric current?
- I
5. What unit is used to measure current?
- amperes (amps)
Rate in the Electrical System
6. What is the equation for calculating current?
- Current = charge moved
elapsed time
- I = q
t
7. When is electrical current one ampere?
- when one coulomb of charge is moved in one second
Rate in the Electrical System8. Example – A DC motor operates at a
rate of 10 amperes for 10 seconds. How much charge moves through the motor?- I = q
t- 10 amps = q
10 sec- q = 100 coulombs
Rate in the Electrical System
9. What is the difference between AC and DC current?
- DC current flows only one way – from the negative electrode to the positive
- AC current flows either way – the electrons constantly change direction
Rate in the Electrical System
10. Why is AC current used in homes and businesses?
- it is much more economical to transfer AC current over long distances than DC current
11. How do you measure voltage in a circuit?
- voltmeter
- it is connected in parallel with the circuit
Rate in the Electrical System
12. How do you measure current in a circuit?
- ammeter
- it is connected in series with the circuit
13. What is a VOM?
- a handheld device that measures both current and voltage
Rate in the Electrical System
14. What is frequency in terms of AC current?- measure of how often the current alternates
15.What unit is used to measure frequency?
- hertz (Hz) – both SI and English
Rate in the Electrical System
16. How is frequency calculated?
f = n / t
- f = frequency
- n = number of cycles
- t = time
Rate in the Electrical System
17. Example – A generator produces an electrical signal that has 240 cycles in 4 seconds. What is the frequency of the signal?f = n / tf = 240 cycles / 4 secondsf = 60 Hz
Rate in the Electrical System
18. How are frequency and period related?
- period is the time it takes for one cycle to occur
f = 1 / T
- T = period (usually in seconds)
T = 1 / f
Rate in the Electrical System
19. Example – The frequency of an electrical wave is 60 Hz. What is the period of the wave for one cycle?
- T = 1 / f
- T = 1 / 60 Hz
- T = 0.0167 sec