When to use light bulb in Korean
Korean: 전등[ jeon-deung ]

When to use it
A light bulb is the thing that gives light in a room or lamp. In Korean, people say 전등 for the light in a room, and it is often used in everyday home situations. You can use it when talking about turning a light on or off, buying one, or saying it is broken.
Example sentences
거실 전등이 밝아요.
The living room light is bright.
전등을 켜 주세요.
Please turn on the light.
학교 교실 전등이 고장 났어요.
The classroom light at school is broken.
밖이 어두워서 전등을 켰어요.
It was dark outside, so I turned on the light.
이 전등은 얼마예요?
How much is this light bulb?
호텔 방 전등이 안 켜져요.
The hotel room light will not turn on.