The charge transferred per unit time is the measurement of electric current. In conductive material, it represents the flow of electrons. Electric current is a scalar quantity, and its SI unit is Coulomb/Second. There are two types of current, namely (i) DC (direct current) and (ii) AC (alternating current). In DC, as the names suggest, it moves along a straight line, and thereby the current moves linearly. Whereas, in the case of AC, the flow of charge moves in a periodical manner.

Alternating Current

The alternating current shows the back and forth motion, or the current that flows alternatively, i.e., continuous change in the magnitude and periodic change in the direction concerning time. The periodic change and AC can be understood with the help of the amplitude of AC. The amplitude of the AC is defined as the value of current at its peak in either direction. The amplitude of AC is represented by I0. The periodic time of AC is the time period of completing one complete cycle variation, which means back and forth. It can be represented with the help of the sine and cosine curve.

Frequency and Unit of AC

The frequency of the AC is defined as the number of cycles completed in one second by the alternating current.

Unit: Cycle/s or Hertz (Hz)

In India, 50 Hz frequency and 220 Volt supply voltage are required in each household, whereas in the case of the USA, 60 Hz frequency and 110 Volt supplying voltage are needed.

Conditions required for Alternating current

1. The amplitude is constant.
2. The current continuously changes its magnitude and periodically reverses its direction.
3. As the curve of Alternating current is sine or cosine, this implies that one half of the cycle is positive while the other half is negative.

Measurement of Alternating current

1. Alternating current can be measured with the help of an AC ammeter.
2. The working of an AC ammeter is based on the heating effect of current; therefore, they are called hot wire instruments.

AC Power

The energy transformation or rate of doing work is so-called Power in AC. The process is per unit time interval. AC power is used to evaluate the required power to supply a load.

Power factor: The power factor is the ratio of two powers, i.e. true power over apparent power.

Power factor can be written as a percentage or decimal:

Power factor=True power ⁄ Apparent power

The power factor is a dimensionless quantity.

AC power over DC power supply

1. AC’s back and forth factor gives us a clear idea to choose AC over DC.
2. AC power supply gives the ability to travel back and forth over long distances, making it available for more houses.
3. AC power supply is a much more convenient and accessible way of transmitting the power at a low cost.
4. AC power is the only one compatible with both capacitors and inductors.

Power consumption in AC circuit

An electric circuit produces power, and it is mathematically represented in the following form:

P=VI

Where P stands for power, I is the electric current that flows through a circuit, and V stands for voltage across the circuit.

Applications of AC power in daily life

1. Generally, AC power is used in the distribution of power.
2. Using a simple transformer, the AC can be converted into other voltages.
3. Transformers work on AC power, not on DC power.
4. The main field where we find the primary use of AC power is in the industries of manufacturing and production of electricity.
5. For household purposes, AC power is preferred instead of DC power.
6. While converting low voltage to high or high voltage to low (up to the required voltage), more heat is produced. Hence, DC power is less efficient.
7. DC power supply creates significant problems such as fire hazards, higher costs, and more, which is not the case with AC power.
8. Alternating current is used in electric motors to convert electrical energy to mechanical energy.
9. AC is used in operating television, refrigerators, dishwashers, toaster, washing machines, coolers, etc.
10. Using AC power is cost-efficient and generates the power by decreasing the voltage.

Conclusion

The direction of current flowing inside a circuit is differentiated in two ways: one is by direct current, and the other is by alternating current. If the current flow occurs in only one direction, it is called DC or direct current. Whereas, if an electric current changes its direction periodically, it is the AC or alternating current. Specific conditions need to be met when using the alternating current, such as constant amplitude must be maintained, and the current reverses its direction periodically.

AC has the most significant advantage in day-to-day life as it is transformed while DC does not. Alternating current can be controlled and maintained using capacitors, inductors, and resistors.

Therefore, AC power supply can be used widely on a large scale. AC power supply is used in many electronic devices such as refrigerators, televisions, dishwashers, charging phones, etc.