An alternating electric current has a frequency of 50 Hz. How many times does it changes it direction in one second?

What is the difference between direct current and alternating current? How many times does AC used in India change direction in one second?

The frequency of a source of sound is 50 Hz. How many times does it vibrate in one minute?

The frequency of source of sound is 100 Hz. How many times does it vibrate in a minute ?

A bulb is connected in alternating current circuit.The frequency of a.c. is 50 Hz. Clearly current becomes zero 100 times in one second, then why does the bulb not lit intermittently? If the frequency of a.c. be 2 Hz, then will the bulb lit intermittently?

The frequency of a source is of sound 40 Hz. How many times does it vibrate in half a minute?