Question

dissent should always be expressed peacfully in democracy.explain

Answer 1

The first line of attack to improve a government policy should be peaceful protests. There are several reasons for this:
1 The right of peaceful protest is protected in order to further the goals of communication and deliberation which form the backbone of democracy.
2 It prevents a reactionary response that a militant form of dissent immediately creates. 
3 It shows that you are open to constructive or compromise solutions as opposed to simply "my way or the highway".