What’s Power factor ?
The active power divided by the apparent power (i.e product of the rms input voltage and rms input current of a driver.)
2.How to explain “luminous Efficacy“ ?
A measure of how well a light source products visible light expressed as lumens /Watt.
3.LEDs are more expensive than other lighting options.why ?
LEDs can operate as standalone devices,but when grouped or clustered they require additional steps to operate properly. LEDs need proper components such as a circuits can be designed rapidly, but to ensure that they operate correctly and for long periods of time they require testing.