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Question 1

What is transformer ratio?

Answer 1

It is the ratio between Number of turns in the Secondary coil and the number of turns in the Primary coil of a Transformer.

Question 2

What phenomenon is involved in the working of a transformer?

Answer 2

Mutual induction is involved in the working of a transformer.

Question 3

What type of transformer is used in a 6V bed lamp?

Answer 3

Step down transformer is used in a 6V bed lamp.

Question 4

Calculate the number of turns in the secondary if the primary has 10 turns and the transformer converts 200VAC into 2000VAC.

Answer 4

100 turns in the secondary.

Question 5

What is the expression for the reactance of an inductor?

Answer 5

Xₗ = ωL

Question 6

What is the expression for the reactance of a capacitor?

Answer 6

Xᶜ = 1/(ωC)

Question 7

What is meant by wattless component of current?

Answer 7

In purely inductive or capacitive circuit, power consumption is zero.
So even if current is passing through the circuit, no power is consumed.

Question 8

What is the phase difference between AC voltage and AC current for a pure resistor?

Answer 8

Zero.

Question 9

What is the phase difference between AC voltage and AC current for a pure inductor?

Answer 9

The current lags behind the voltage by π/2.

Question 10

What is the phase difference between AC voltage and AC current for a pure capacitor?

Answer 10

The current leads ahead of the voltage by π/2.

Question 11

What is wattless current?

Answer 11

In a purely inductive (or capacitive) circuit, the power consumption becomes zero (power factor cos(φ) = 0).

Question 12

Define power factor? On which factors does it depend?

Answer 12

The cosine of phase angle btw voltage and current is power factor.
P=VI cos @

Cos@ is power factor. It depends on phase difference @ between current and voltage.
Here @ is fi