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

Explain with the help of a labelled diagram the underlying principal and working of a step-up transformer, why cannot such a device be used to step-up d.c. voltage ?

Can a transformer be used to alter DC voltage?

A step up transformer is used to

Can we a transformer be used to step up or step down a D.C. voltage? Explain.

Assertion : An ideal transformer does not vary the power. Reason : An transformer is used to step-up or step-down ac voltages.

A transformer is used to step down a.c.voltage. What appliance do you use to step down d.c. voltage ?

Step-up transformers are used for

An ideal transformer is used to step up an alternating emf of 220V to 4.4kV to transmit 6.6kW of power The current rating of the secondary is