A transformer has a coil of 1000 turns wound on its central core and the terminals of the coil are connected to a mains of 240 V supplying a current of 120 mA. Another coil of 50 turns is wound on the first coil and its terminals connected to a radio of power 24 W. Which of the following is NOT correct The turns ratio of this transformer is 33. A 20 : 1 B The output current is 0.20 A, C The efficiency of the transformer is 83.3 % D This is a step down transformer

A transformer has a coil of 1000 turns wound on its central core and the terminals of the coil are connected to a mains of 240 V supplying a current of 120 mA. Another coil of 50 turns is wound on the first coil and its terminals connected to a radio of power 24 W. Which of the following is NOT correct The turns ratio of this transformer is 33. A 20 : 1 B The output current is 0.20 A, C The efficiency of the transformer is 83.3 % D This is a step down transformer

Glencoe Physics: Principles and Problems, Student Edition

1st Edition

ISBN:9780078807213

Author:Paul W. Zitzewitz

Publisher:Paul W. Zitzewitz

Chapter25: Electromagnetic Induction

Section: Chapter Questions

Problem 85A

See similar textbooks

Similar questions

Check Your Understanding A transformer steps the line voltage down from 110 to 9.0 V so that a current of 0.50 A can be delivered to a doorbell (a) What is the ratio of the number of turns in the primary and secondary windings? (b) What is the current in the primary winding? (c) What is the resistance seen by the 110-V source?
An emf of 9.7 × 10-3 V is induced in a coil while the current in a nearby coil is decreasing at a rate of 2.7 A/s. What is the mutual inductance of the two coils?
Two coils close to each other have a mutual inductance of 32 mH. If the current in one coil decays according to I=I0eat , where I0= 5.0 A and =2.0103s1 , what is the emf induced in the second coil immediately after the current starts to decay? At t=10.0103s? ?
When the current in one coi1 changes at a rate of 5.6 A/s an emf of 6.3 × 10-3 is induced in a second, nearby coil. What is the mutual inductance of the two coils?
A step-up transformer has 30 turns on the primary coil and 750turns on the secondary coil. If this transformer is to produce anoutput of 4800 V with a 15-mA current, what input current andvoltage are needed?
The secondary coil of a transformerhas 440 turns, and produces anoutput AC voltage of 25.0 V whenan input voltage of 9.00 V isapplied to the primary. How manyturns does the primary coil have?
220 V is supplied across 1200 windings of theprimary coil of the autotransformer. If 1650 windings are tapped, what voltage will be supplied tothe primary coil of the high-voltage transformer?
Do it quickly.
A step down transformer on a 212 volt line has 589 loops on the primary and 172 loops on the secondary, and ¢raws 1.24 ampere current. What is the voltage of the secondary (output potential in volt)?
A transformer has Np = 500 turns on the primary coil and Ns = 60 turns on the primary coil secondary. (a) What kind of transformer is this? (b) By what factor does this transformer change the voltage and the AC current?
The primary windings of a transformer which has an 88%efficiency are connected to 110-V ac. The secondarywindings are connected across a 75-W lightbulb.(a) Calculate the current through the primary windings ofthe transformer. (b) Calculate the ratio of the numberof primary windings of the transformer to the number ofsecondary windings of the transformer.
The primary coil in a transformer contains 124 loops, and the secondary coil consists of 19 loops. What is the voltage across the secondary if the voltage across the primary is 120.0 V? (Assume 3 sig figs).