A transformer has a 100-turn primary coil and 1000-turn secondary coil. The primary is connected to a 120-V AC source and the secondary os connected to an electrical devic with a resistance of 1000 ohms.what will the voltage output of the secondary be?what current flows in the secondary circuit?what is the power in the seconday coil?what is the power in the primary coil ?what is the current drawn by the primary coil?
If the secondary has 10 times as many turns, it will multiply the voltage by 10 times. 120 VAC x 10 1200 VAC Use Ohm's law, EIR for the current. Voltage Current times Resistance, Volts Amps x Ohms 1200 I x 1000 I 1.2 Amps Power in Watts E x R (Volts x Amps) 1200 V x 1.2 A 1440 Watts For a 100% efficient transformer, the input power matches the output power. In real life, a bit more power goes in than comes out. That's why the transformer gets warm. For this problem, with a perfect transformer, the input power will be 1440 Watts. That makes the input current 12 Amps. What they want you to see in this exercise is that the transformer, because it has a 1:10 ratio in the windings, is that the secondary will have 10x the voltage and 1/10th the current. The primary will have 1/10th the voltage and 10x the current. And they want to make sure you understand the power in matches the power out.
The ratio of teh secondary to primary turns gives you the voltage multiplication on the secondary. Thus N 1000/100 10 So the secondary voltage is Vs Vp*N 120V *10 1200V The secondary current Is Vs/Rs 1200V/1000 Ohms 1.2 A Power in secondary Ps Vs*Is 1440 W Power in Primary has to be the same as secondary (or less due to losses) 1440 W Ip Pp/Vp 1440/120 12 Amps
The ratio of voltages in the windings of a transformer is the same as the ratio of turns of wire in the windings, so in this case the voltage ratio is 1 to 10. If you connect the primary to a source of 120 volts, the voltage induced in the secondary winding is 10 times as much, or 1200. If a (pure) resistance of 1000 ohms is connected to the secondary winding, the current (I) that flows is found by Ohm's Law: I E/R. Since E is 1200 volts and R is 1000 ohms, I 1200 / 1000, or 1.2 amperes. The power P in the secondary coil is found by multiplying the voltage by the current, so P 1200 times 1.2, or 1440 watts. Transformers are very efficient, and the power in the primary coil is essentially the same as that in the secondary, or 1440 watts. The current drawn by the primary coil is found by dividing the power by the voltage: 1440 divided by 120 12 amperes. Hope this answers all parts of your question.
A Step up transformer is exterior a ability station and will develop the voltage for the flexibility lines so it may flow swifter and extra effective parts. A step down transformer is after the flexibility lines to lessen the voltage and making it secure for domicile use.
