A transformer is needed that will cause an actual load resistance of 25 Ω to appear as 100 Ω to an ac voltage source of 240 V rms. Draw the diagram of the circuit required. What turns ratio is required for the transformer? Find the current taken from the source, the current flowing through the load, and the load voltage.

The amount of inrush current in the primary of a transformer is limited by the........, A- amount of applied voltage, B- resistance of the wire in the primary winding, C- flux change of the magnetic field in the core, D - all of the above What precaution must be observed when working whit current transformers? A- never have a load on the secondary, B- always ha a load on the secondary, C- de-energize the primary whenever there is a load on the secondary, D - none The fact that the movable coil of a constant-current transformer moves further away from the stationary coil with a increase in load current is based on which fundamental priciple of magnetism? A- like magnetic poles attract, B- like magnetic poles repel, C- the amount of current flowing through a coil inverdely proportional to its flux density. D- none

1. An ideal transformer with a 450 turn primary connected to a 600 V, 60 Hz supply line needs to output 240 V from the secondary. A 100 load is connected across the secondary. How many turns the secondary must have to output the desired voltage? What is the current through the load? What is the current drawn through the primary?

The table below shows some performance parameters of a certain power transformer. Full-load voltage regulation Full-load copper loss Load power factor 0.5 Lagging 5% If the load is nure resistive, the full-load voltage regulation is: 0.1% 286 2% 4%