Answer:
3. Is 180◦ out of phase with the original wave at the end.
Step-by-step explanation:
Here when wave is reflected by the rigid boundary then due to the rigidly bounded particles at the end or boundary they have tendency not to move and remains fixed at their position.
Due to this fixed position we can say when wave reach at that end the particles will not move and they apply equal and opposite force at the particles of string
Due to this the reflected wave is transferred back into the string in opposite phase with respect to the initial wave
so here correct answer will be
3. Is 180◦ out of phase with the original wave at the end.