1 bulb and 3 switches

Puzzle:

There are 3 switches and one bulb , the bulb is in the closed room and switches are outside of the room now you have to identify the correct switch of the bulb. you have only once chance to go inside the room.

 

Solution: 
Step 1: Turn on the first switch and wait for 5 min, then off the switch.

Step 2: Turn on the second one and go to the room.

Conclusion: If the correct switch was the first one, the bulb got heated, if it’s the second one, it means the bulb is lighting in the room, else it would be the third one.