Quiz on transformer principles

Which coil is responsible for establishing the field in mutual induction?

• Secondary coil

• Tertiary coil

• Primary coil

• Auxiliary coil

Answer explanation

The primary coil is responsible for establishing the magnetic field in mutual induction. It generates the magnetic field that induces a current in the secondary coil, making it the key component in this process.

What is the effect of the alternating field on the secondary coil in mutual induction?

• It decreases the voltage.

• It induces an alternating emf.

• It creates a direct current.

• It neutralizes the magnetic field.

Answer explanation

The alternating field in the primary coil creates a changing magnetic field, which induces an alternating emf in the secondary coil due to mutual induction. This is the principle behind transformers and inductive coupling.

What does the symbol 'Ip' represent in the transformer diagram?

• Primary voltage

• Primary current

• Secondary voltage

• Secondary current

Answer explanation

In transformer diagrams, 'Ip' denotes the primary current. It represents the current flowing through the primary winding, which is crucial for understanding the transformer's operation and efficiency.

What is the principle called when the field produced by each turn in the primary winding induces an emf in each turn in the secondary winding?

• Self induction

• Mutual induction

• Electromagnetic induction

• Capacitive coupling

Answer explanation

The principle where the magnetic field from the primary winding induces an emf in the secondary winding is called mutual induction. This occurs when the coils are in proximity, allowing energy transfer between them.

In the context of mutual induction, what does "emf" stand for?

• Electromagnetic force

• Electromotive force

• Electric magnetic field

• Energy magnetic field

Answer explanation

In the context of mutual induction, 'emf' stands for 'Electromotive force'. It refers to the voltage generated by a changing magnetic field, which is crucial in understanding electromagnetic induction.

What is the role of 'excess' primary turns in mutual induction?

• They decrease the secondary current

• They increase the secondary current

• They have no effect on the secondary current

• They cause the secondary current to fluctuate

Answer explanation

Excess primary turns in mutual induction increase the magnetic flux linked with the secondary coil, leading to a higher induced electromotive force (EMF) and thus increasing the secondary current.

What is the effect of insufficient turns in the secondary winding?

• Increased emf

• Decreased emf

• No change in emf

• Fluctuating emf

Answer explanation

Insufficient turns in the secondary winding lead to a decreased emf. This is because the induced voltage is directly proportional to the number of turns; fewer turns result in lower voltage output.

Rohan is working on a project where he needs to connect a transformer to a secondary voltage supply. What is the common secondary voltage supply for power tools on a construction site

• 110 volts

• 230 volts

• 50 volts

• 300 volts

Answer explanation

The common secondary voltage supply for power tools on a construction site is 110 volts. This lower voltage is used to reduce the risk of electric shock and is standard in many construction environments.

Which of the following is NOT a cause of transformer loss?

• Hysteresis

• Eddy Current

• Reactive

• Friction

Answer explanation

Friction is not a cause of transformer loss. Transformer losses primarily arise from hysteresis and eddy currents in the core material, while reactive losses are related to the inductive nature of the transformer.

What is the purpose of the core in a transformer?

• To increase resistance

• To provide a path for magnetic flux

• To reduce voltage

• To increase current

Answer explanation

The core in a transformer serves to provide a path for magnetic flux, which is essential for efficient energy transfer between the primary and secondary coils.