Exercise (Conceptual Questions)

Why is the core of a transformer laminated?

Which type of losses do not occur in the transformer?

A $100 \Omega$ resistor is connected to a $220 \mathrm{V}, 50 \mathrm{Hz}$ ac supply. What is the rms value of current $\left(\mathrm{A}\right)$ in the circuit?

A current in circuit is given by $i=\left(3+4\sin \omega t\right) \mathrm{A}$. Then the effective value of current is (in $\mathrm{A}$) :

A $12 \mathrm{\Omega }$ resistor and a $0.21 \mathrm{H}$ inductor are connected in series to an AC source operating at $20 \mathrm{V},50 \mathrm{Hz}$. The phase angle between the current and the source voltage is

A capacitor of capacity $C$ has reactance $X$. If capacitance and frequency become double then reactance becomes $\frac{X}{2\alpha }$. Find value of $\alpha$.

An inductance of $1 \mathrm{mH},$ a condenser of $10 \mu \mathrm{F}$ and a resistance of $50 \mathrm{\Omega }$ are connected in series. The reactance of inductor and condensers are same. The reactance of either of them will be

The hot wire ammeter measures: