# Quantum Entanglement : Changing states after measurement

Hi I am quite new to Quantum Mechanics and I came across with this confusion.

Let's say there are 2 entangled particles A and B.

1. When A is measured to be state 0 (doesnt measure B) does it automatically collapse B to 1 or does it imply B should be 1 ?

2. If A is measured (result is 1) and doesn't measure B, by any chance if we change the state of A to state 0 will it change the state of B ?

Thank you very much.

For example, if the original state was $$\frac{1}{\sqrt2}(|01\rangle + |10\rangle)$$, measuring the first particle in state $$|0\rangle$$ will indeed collapse the second one to $$|1\rangle$$. But if the original state was $$\frac{1}{\sqrt2}(|00\rangle + |11\rangle)$$, the state of the second particle will be $$|0\rangle$$, and if it was $$\frac{1}{2}|0\rangle\otimes(|0\rangle + |1\rangle) + \frac{1}{\sqrt2}|11\rangle$$, the second particle will end up in $$\frac{1}{\sqrt2}(|0\rangle + |1\rangle)$$.