- 1How is a constant voltage achieved with changing loads in a power transformer ?in terms of H.V...
How is a constant voltage achieved with changing loads in a power transformer ?in terms of H.V winding.

- 2variable resistor constant voltage effect on current and power
A simple electric circuit consists of aconstant-voltage power supply and a variable resistor. What effect doesreducing theresistance have on the current in the circuit and on the poweroutput of the power supply?

- 3Voltage of a transformer
A 15-kVA, 8000/230-V distribution transformer has an impedencereferred to the primary of 80+j300Ω. The components of theexcitation branch referred to the primary sideare Rc= 350kΩand Xm=70kΩ.a.if the primary voltage is 7967 V and the load impedence is ZL=3.2+ j1.5Ω, what is the secondary voltage of the transformer?What is the voltage regulation of thetransformer?b. they applied a capacitor of -j3.5Ω in place of the loadanswer the same question in part A.

- 4a transformer has a primany voltage of 115 v and secondary voltage of 24 v if the number of tures in the primany is 345 how many turns are in the secondaryThe voltage ratioVsecondary/Vprimary = 24/115 = 0.209This equals the turns ratio
a transformer has a primany voltage of 115 v and secondary voltage of 24 v if the number of tures in the primany is 345 how many turns are in the secondaryThe voltage ratioVsecondary/Vprimary = 24/115 = 0.209This equals the turns ratioNsecondary/Nprimary = Nsecondary/345 = 0.209Therefore Nsecondary = 72a man wants to illuminate 5 houses on his model railroad by wiring 5 20 ohm lamps in series.how much resistance must be added in the series in order to limit the current to the .5A needed by each light?why does tv's, computers, steros, get so dusty

- 5If a transformer steps up the voltage it must:
If a transformer steps up the voltage it must:A. also step up the currentb. leave the current unchangedc. step down the current

- 6transformer voltage regulation
a single phase 3kVA, 240/120 V transformer has the following parameters:R high voltage: .25 ohms, X high voltage: j.75 ohms, R low voltage: .05 ohms and X low voltage: j.18 ohms.determine the voltage regulation when transformer is supplying full load at 110 volts and .9 leading power factor. if the load terminals are accidentallyshort-circuited determine the currents in the low and high voltage windings.

- 7Equivalent Phase Voltage Transformer
What are the circulator currents?I'm somewhat confused by the per unit impedances.When we model this as equivalent 1 phase transformers:We get a primary with phase voltage of 25kv/sqrt(3) and the secondary has an "equivalent" phase voltage of 230kv/sqrt(3).Does that mean my base voltage forthe circulator current analysis is done with these base voltages instead of the actual phase voltages of 25k/sqrt(3) and 230kv?Lifesaver if anyone can provide some info on this "equivalent" phase modelling

- 8a transformer with a ratio of 80:250 is supplied with a voltage of 240 volts and
a transformer with a ratio of 80:250 is supplied with a voltage of 240 volts and 2 amperes.what is outgoing voltage?what is outgoing current?what is output power?

- 9A step-up transformer increases voltage 20 times
A step-up transformer increases voltage 20 times. If the voltage of the primary coil is 1200V, what's the voltage of the secondary coil? Please help. Thank You!

- 10The secondary coil of a step up transformer provides the voltage that operates a
The secondary coil of a step up transformer provides the voltage that operates an electrostatic air filter. the turn's ratio of the transformer is 50:1. The primary coil is plugged into standard 120 V outlets. the current is secondary coil is 1.70 x 10 (-3) A. Find the power consumed by air filter.

- 11A device uses an AC voltage of 4320 V, which is obtained from a standard 120.0 V outlet by means of a transformer
A device uses an AC voltage of 4320 V, which is obtained from a standard 120.0 V outlet by means of a transformer. If the primary coil has 21 turns, how many turns are in the secondary coil?

- 12primary and secondary windings of a transformer - Calculate the current drawn from the voltage...
The number of turns in the primary and secondary windings of a transformer are 80 and 20 respectively. The reluctance of the core is 64x10^3 A/Wb . The primary isconnected to a voltage source, Vpri(t) = 170 sin (377t) V and the secondary is connected to a resistance of 2Ω.Calculate the current drawn from the voltage source in steady state.