Question

In: Physics

A transformer is plugged into a regular U.S. Wall outlet. There are 200 turns in the...

A transformer is plugged into a regular U.S. Wall outlet. There are 200 turns in the primary coil, and 4000 turns in the secondary coil. A) What is the rms voltage and peak voltage on the secondary coil? (two answers) B) An electrical worker accidently grabs one of the loops of the secondary coil with a single bare hand. Her other hand is in midair, and both of his shoes are firmly on the ground. The resistance in her body is negligible compared to his shoes. Each shoe has a 2mm-thick rubber sole, with a sole-area of 0.02 m2 . The rubber has a resistivity of 1 MW•m. What is the rms current that runs through the worker's torso? (Warning: there are two shoes.) Hint: A drawing is almost certainly helpful. C) There is a 50-Amp fuse on the wall outlet. Will this fuse trip before the full current (calculated in part B) passes through the worker's body? (Careful: There is a complication here, since the fuse is on the primary-coil side of the transformer.).

Solutions

Expert Solution

a) voltage input = regular U.S= Vprimary =120V /this is rms

numer  turns in the primary coil Nprimary =200

numer  turns in the secondary coil Nsecondary =4000

Vsecondary

apply trnsformer equation Vprimary /Vsecondary =Nprimary /Nsecondary

120 / Vsecondary =200 / 4000

rms Vsecondary =120x40 /2 =2400 volt

peak voltage of the Vsecondary = Vsecondary = x2400 volt =3394.11 volts

b) resistance of his shoe can be find by equation R = resistivity   = 1 mega ohm =106 ohm

length L =2mm=2x10-3 m area A = 0.02m2

R = 106 x2x10-3 /0.02 =100000 ohm for one she

boath shoe are in parallel so effective resistance to voltage = 100000 x100000 / (100000 +100000 ) =50000ohm

so current flow through his body = working voltage / effective resistance =2400 volt /50000ohm =0.048ampere

c) 50 A fuse in primary

the current flow in primary while worker ketting shock is

apply transformer equation  Vprimary /Vsecondary = Isecond / Iprimary -----/   Isecond =0.048ampere   Vprimary =120

Vsecondary= 2400 volt

Iprimary = 0.048 x2400 / 120 =0.96 amps

fuse will not burn out because current flowing is lessthan the fusing current (0.96A < 5A)


Related Solutions

You build a transformer with 100 turns of wire on side 1, and 500 turns on...
You build a transformer with 100 turns of wire on side 1, and 500 turns on side 2. A) If you put a voltage of 100 V (AC) on side 1, what voltage would you get on side 2? B) If you put a voltage of 100 V (AC) on side 1 with a current of 1 Amp (AC), what current would you get on side 2? C) If you put 100 V of DC voltage on side 1, what...
1. An ideal transformer has a primary with 25 turns and secondary with 15 turns. The...
1. An ideal transformer has a primary with 25 turns and secondary with 15 turns. The load resistor is 24 ? and the source voltage is 85 Vrms.What is the rms electric potential across the 24 ? load resistor? Answer in units of Vrms 2. A transformer consists of two coils of wire wound on a common toroidal iron core. The mutual inductance of the pair is 483 mH and the current in the first coil decreases from 29 A...
When plugged into a standard outlet in the United States, a toaster oven uses 1600 W...
When plugged into a standard outlet in the United States, a toaster oven uses 1600 W att of power (on average). (a.) On a power (watt) vs. time (seconds) graph, plot the power used by the toaster oven. For full points, your graph must use every tick mark, must show two cycles and must label both the time and peak current values. Assume that t = 0 corresponds to a time when the power is at its maximum value. (b.)...
1.A circuit of resistors connected in series is plugged in a 120 V outlet. What can...
1.A circuit of resistors connected in series is plugged in a 120 V outlet. What can you tell about the voltage on each of resistor and current in each resistor? 2.A circuit of capacitors connected in parallel is plugged in a 120 V outlet. What can you tell about the voltage on each capacitor and current in each capacitor?
An ideal transformer has 50 turns in its primary and 250 turns in its secondary. 12...
An ideal transformer has 50 turns in its primary and 250 turns in its secondary. 12 V ac is connected to the primary. Find: a. The voltage ac available at the secondary. b. Current in the 10 ohms device connected to the secondary. c. Power supplied to the primary. d. Power supplied to the secondary.
An ideal transformer has 50 turns in its primary (input) and 450 turns in its secondary...
An ideal transformer has 50 turns in its primary (input) and 450 turns in its secondary (output). 10.0-V ac is connected to the primary (input). a) What is the voltage on the secondary (output)? b) What is the secondary (output) current if a 10.0- resistor is connected to the secondary (output)? c) What is the power supplied to the primary (input)?
current transformer with a bar primary has 250 turns in it secondary winding. the resistance and...
current transformer with a bar primary has 250 turns in it secondary winding. the resistance and reactance of the secondary circuit are 1.4 ohms and 1.1 ohms respectively including the transformer winding. when 5A current flows in the secondary winding, the magnetism mmf is 80 AT and iron lost is 1.1w. determine the following (i) ratio error (ii) phase angle error
Exercises 1. A 25 kVA single-phase transformer has the primary and secondary number of turns of...
Exercises 1. A 25 kVA single-phase transformer has the primary and secondary number of turns of 200 and 400, respectively. The transformer is connected to a 220 V, 50 Hz source. Calculate the (i) turns ratio, and (ii) mutual flux in the core. 2. A 25 kVA, 2200/220 V, 50 Hz single-phase transformer’s low voltage side is short-circuited and the test data recorded from the high voltage side are P=150 W, I1 = 5A and V1 = 40 V. Determine...
The secondary of a 500kVA, 4400/500 V, 50Hz, single-phase transformer has 500 turns. A) determine emf...
The secondary of a 500kVA, 4400/500 V, 50Hz, single-phase transformer has 500 turns. A) determine emf per unit. B) primary turns. C) secondary full load current D) maximum flux E) gross cross-sectional area of the core for flux density of 1.2 tesla F) if the core is square cross-section find the width of the limb
A current transformer rated 500/5 A, 20 VA, 50 Hz has a turns ratio of 1:99....
A current transformer rated 500/5 A, 20 VA, 50 Hz has a turns ratio of 1:99. Its resistance aand leakage reluctance of the secondary winding are 0.4 Ω and 0.35 Ω respectively. At rated non-inductive burden, the inphase and quadrature components of the exciting mmf are 6 AT and 8 AT respectively. Determine the current and phase angle error.
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT