Explanation
The two main applications for AC (alternate current) are power and information. AC is used to generate and transfer power to electrical devices, and is also used to carry information signals in telecommunications.

Explanation
Wavelength is a measure of the distance that a signal's energy can travel in the time it takes for one cycle of the signal to occur. It is calculated by dividing the speed of light by the frequency of the signal. Wavelength is generally expressed in meters (m).

Explanation
A voltage regulator controls the voltage produced at the output of the alternator. It's a device that maintains the output voltage of an alternating current (AC) power source within a safe range. The voltage regulator compares the actual output voltage to the desired voltage level and adjusts the voltage accordingly.
Voltage Meter, Voltage Stabilizer, and Voltage Backup Device are not devices that control the voltage produced at the output of the alternator. They are different types of equipment and have different functions.
A voltage meter is a device used to measure the voltage in an electrical circuit. A voltage stabilizer is an electronic device that maintains a constant voltage level. A voltage backup device is a device that provides temporary backup power in case of an electrical outage.

Explanation
Physical security means keeping unauthorized or ill-intentioned people out of places that they do not belong.
This can involve a variety of measures, such as locks, alarms, access control systems, cameras, and guards.
Physical security is an important part of any security system, as it helps to protect valuable assets and personnel from theft, vandalism, and other malicious activities.