Answer
potential difference will increase
Work Step by Step
Before bulb is removed there is current in whole circuit, and there is potential drop across resistance in 2nd wire(containing bulb B). Now when bulb B is removed it will become open circuit, now the whole current will flow through bulb A as that circuit is closed.
since there is no current through the wire potential at point 1 will be same as of positive terminal of battery, and same at point 2 as of negative terminal of battery.
potential difference between points 1 and 2 will be same as potential of battery which is more than initial
