A.C. Generator

A $220 \mathrm{V}$ dc machine has an armature resistance of $1\mathrm{\Omega }$. If the full load current is $20 \mathrm{A}$, the difference in the induced voltages when the machine is running as a motor, and as a generator is

A $220 \mathrm{V}$ dc machine has an armature resistance of $1\mathrm{\Omega }$. If the full load current is $20 \mathrm{A}$, the difference in the induced voltages when the machine is running as a motor, and as a generator is

A current that always flows through an electric device in the same direction is called direct current or $\mathrm{DC}$. The polarity (positive and negative) of a direct current is fixed. A current that reverses direction at equal intervals of time is called the alternating current or $\mathrm{AC}$. The polarity (positive and negative) of an alternating current is not fixed. Both $\mathrm{DC}$ and $\mathrm{AC}$ can be used for lighting and heating. Some electric devices like the television need $\mathrm{DC}$ to operate. In such cases, an adapter or a device is fitted into them to convert $\mathrm{AC}$ from the mains supply to $\mathrm{DC}$.

On the basis of above information, answer the following :

A current that always flows through an electric device in the same direction is called direct current or $\mathrm{DC}$. The polarity (positive and negative) of a direct current is fixed. A current that reverses direction at equal intervals of time is called the alternating current or $\mathrm{AC}$. The polarity (positive and negative) of an alternating current is not fixed. Both $\mathrm{DC}$ and $\mathrm{AC}$ can be used for lighting and heating. Some electric devices like the television need $\mathrm{DC}$ to operate. In such cases, an adapter or a device is fitted into them to convert $\mathrm{AC}$ from the mains supply to $\mathrm{DC}$.

On the basis of above information, answer the following :

The frequency of an a.c. generator depends upon:

Select the disadvantages of AC from the following.

List few demerits of AC current.

For electroplating, alternating current is used.

Why cannot we use AC current in electrolysis?

When the sine of angle in an electric generator is $0°$, the induced emf is :

AC is easier to manufacture than DC. It is also less expensive to produce than DC.

Explain how AC is better than DC when transmitted over long distances.

We can use a transformer to step-up or step-down-

List a few merits of AC in comaprison with DC.

AC can be easily transmitted over long distances. Why?

AC can be transmitted over long distances without much loss of energy.

A DC motor has split rings and an AC generator has two separate coaxial _____ rings.

An electric motor used to generate electricity.

An electric motor works on the principle that a current carrying coil kept in a magnetic field experiences a force. Generator works on the principle of electromagnetic _____.

An electric motor converts electrical energy to mechanical energy. Generator converts mechanical energy into electrical energy.