Transformer

What is transformer?

• A device which changes mechanical energy into electrical energy

• A transformer is a type of electronic device used for changing the voltage of an electrical signal.
• A device which increases or decreases the magnitude of an alternating current

• A transformer is a type of robot that can change shape and size.

A transformer works on the principle of

• Ohm's Law

• gravitational force
• magnetic field

• electromagnetic induction

What is primary coil?

• The primary coil is the coil in a transformer that is connected to the input voltage source.
• The primary coil is the output coil of a transformer.

• The primary coil joins the input source to the transformer.

• The primary coil is a coil with low mutual inductance.

What is turns ratio?

• Number of turns in secondary coil/Number of turns in primary coil

• Number of turns in primary coil/Number of turns in secondary coil

• Number of turns in secondary coil/(Number of turns in secondary coil + Number of turns in primary coil)

• Number of turns in primary coil/(Number of turns in secondary coil + Number of turns in primary coil)

EMF and turns of coil in a transformer are related by?

In an ideal transformer,

• emfs in primary and secondary coils are equal

• currents in primary and secondary coils are equal

• power in primary and secondary coils are equal

• none of these

What is a step-up transformer?

• Number of turns of secondary coil > primary coil

• Number of turns of secondary coil < primary coil

• Number of turns of secondary coil = primary coil

Step-up transformers are used in

• computer

• power generating station

• bulbs

• transformer in locality

The emf relation in step-down transformer is

• E_p < E_s

• E_p > E_s

• E_p = E_s

Step-down transformers are used in

• laptop charger

• television

• X-ray tubes

• power generating station