Andhra Pradesh Board Solutions for Chapter: Alternating Current, Exercise 1: MODEL QUESTIONS (IPE PATTERN)

A transformer converts $200 \mathrm{V}$ A.C. into $2000 \mathrm{V}$ A.C. Calculate the number of turns in the secondary coil if the primary coil has $10$ turns.

Write the expression for the reactance of  (i) an inductor and (ii) a capacitor.

What is the phase difference between AC emf and current in the following:  

1. Pure resistor circuit

2. Pure inductor circuit

3. Pure capacitor circuit

When does a LCR series circuit have minimum impedance?

What is the phase difference between voltage and current when the power factor in LCR series circuit is unity?

In an ac circuit, a condenser a resistor, and a pure inductor are connected in series across an alternator. If the voltage across them are $20 \mathrm{V}$, $35 \mathrm{V}$ and $20 \mathrm{V}$ respectively, find the voltage supplied by the alternator in volts.

In a series LCR circuit $R=200 \mathrm{\Omega }$ and the voltage and the frequency of the mains supply is $200 \mathrm{V}$ and $50 \mathrm{Hz}$ respectively. On taking out the capacitance from the circuit the current lags behind the voltage by $45°$. On taking out the inductor from the circuit the current leads the voltage by $45°$. Calculate the power (in watt) dissipated in the LCR circuit.

A transformer with primary to secondary turns ratio of $1:2$ is connected to an alternator of voltage $200 \mathrm{V}$. A current of $4 \mathrm{A}$ is flowing through the primary coil. Assuming that the transformer has no losses, find the secondary voltage (in Volts) and current (in Ampere).