Is energy produced when a transformer steps up the voltage?

A transformer changes the voltage

A step up transformer is used to

Why cannot a transformer be used to step up d.c. voltage ?

A current of 2A is flowing at 220 V in the primary coil of a transformer. If current in the secondary coil is 1 A and efficiency of the transformer is 80% then the voltage produced in the secondary coil will be

Step-up transformers are used for

The transformer ratio of a transformer is 5. If the primary voltage of the transformer is 400 V, 50 Hz the secondary voltage will be

The transformer ratio of a transformer is 5. If the primary voltage of the transformer is 400 V, 50 Hz, the secondary voltage will be

In an ideal step down transformer, the input voltage is 400V and the output voltage is 20 V. The output voltage is used to operate a device, having an impendance of 100 ohms. What is the current in the primary circuit?

Assertion : Step-down transformer can also be used as step-up transformer. Reason: Ratio of voltage across primary and secondary coils is the same as ratio of respective number of turns.