Question

Vibrating part of jaltarang, sitar, santoor

Answer 1

Jaltarang -> Cup vibrates in Jaltarang

In Jaltarang, water is put into cups. Pitch is managed by volume of water in cups.  Different size of cups are used. Player hits the cup and natural sound of cup to get the sound.

Sitar -> String vibrates in Sitar

In sitar, when you pluck the string it vibrates.

Santoor -> String vibrates in Santoor

In Santoor, 60 to 90 strings are present Santoor which vibrates to produce sound.

Answer 2

Edges of the cups of Jal tarang vibrates when it is played while strings of Sitar and Santoor will vibrate when they are played.

Jal Tarang is a set of melodic musical instruments that consist of a set of metal or ceramic bowls with water. They are played with beaters with one in each hand.  

Sitar and Santoor are stringed musical instruments that were used a widely across many parts of Asian countries.