Solution:Concept: There are two types of current:
Alternating current - The current which changes its direction after a fixed period of time.
Direct current – The electrical current which flows continuously in the same direction.
Alternating current is used when the power that is produced at the power station is transferred to different users. Alternating current can be produced by using a device known as an alternator.
If the voltage and current are varying or different, many waveforms of alternating current can be formed.
Alternating current has a sinusoidal waveform, it depends on three factors: Amplitude, frequency and the phase. The equation is:
sin function means that voltage has a sinusoidal waveform.
2π is a constant
f is the frequency
ϕ shows the phase .
Hence, the correct option is 1 .