Answer
a. Just as brightly.
b. More brightly.
Work Step by Step
a. The 2 bulbs are identical. Their resistances are the same, and the same current flows through them, so they dissipate an equal amount of power. The bulbs are equally bright.
b. Now that Bulb B has been removed, the circuit’s resistance has gone down, and the current has gone up. Bulb A now glows more brightly than before.
