Question

what is working principle of emergency light ​

Answer 1

Answer:

Principle of automatic emergency light circuit

When there is an ac power supply, the battery charges through the rectifier made up of diodes meanwhile the LEDs will not glow as Relay sensed the ac power supply. At the same time the LEDs will also glow as the LDR senses no light.

Answer 2

Answer:

Principle of automatic emergency light circuit

Principle of automatic emergency light circuitWhen there is an ac power supply, the battery charges through the rectifier made up of diodes meanwhile the LEDs will not glow as Relay sensed the ac power supply. At the same time the LEDs will also glow as the LDR senses no light.