Understanding Transformers in the National Grid

The video explains how transformers are used in the national grid to manage electricity voltage. It covers the process of stepping up voltage for efficient transmission and stepping it down for safe usage in homes. The video details the workings of transformers, including the roles of the iron core, primary and secondary coils, and magnetic fields. It also distinguishes between step up and step down transformers based on coil turns and voltage changes.

What is the primary purpose of using transformers in the national grid?

• To store electricity for later use

• To increase the speed of electricity

• To change the color of electricity

• To minimize energy losses during transmission

What happens to the voltage when electricity passes through a step-up transformer?

• The voltage remains the same

• The voltage decreases

• The voltage increases

• The voltage fluctuates randomly

What is the function of a step-down transformer?

• To maintain the voltage

• To decrease the voltage

• To increase the voltage

• To convert AC to DC

What is the role of the iron core in a transformer?

• To induce a magnetic field between coils

• To store electrical energy

• To connect the transformer to the power grid

• To conduct electricity directly

What causes a current to flow in the primary coil of a transformer?

• The coil is cooled

• A direct current is applied

• An alternating potential difference is applied

• The coil is heated

What is induced in the iron core when an alternating magnetic field is present?

• A direct current

• An alternating magnetic field

• A static electric field

• A thermal field

Why is it important to use the correct terms when explaining how transformers work?

• To impress the examiner

• To make the explanation longer

• To ensure understanding and gain marks in exams

• To confuse the audience

Why can't electricity pass directly between the wire and the iron core in a transformer?

• The transformer is not connected to a circuit

• The electricity is too weak

• The iron core is non-conductive

• The wires are insulated in plastic

How does the number of turns in the coils affect the voltage in a transformer?

• The number of turns has no effect on voltage

• More turns in the secondary coil increase voltage

• More turns in the secondary coil decrease voltage

• More turns in the primary coil increase voltage

What is the result of having twice as many turns in the secondary coil compared to the primary coil?

• The voltage is tripled

• The voltage is doubled

• The voltage remains the same

• The voltage is halved