Tell us about an experiment that made an electric field “visible”.

An electric field is detected by its action on a charged body.
If you bring a charged stick to a suspended body, then it will deviate from its original position.
If you run the comb through dry hair several times, it will begin to attract small pieces of paper.
If finely chopped bristles are poured into glycerin, then a metal electrode (flat or round) is placed and connected to an electrophore machine, then the electrode is charged and the bristles will be located in the direction of the electric field lines.

Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.