A wafer of pure germanium crystal has two parts X and Y. The end X is obtained by doping with arsenic and Y with indium. It is connected to a battery as shown in the figure. Which of the following statements is correct?

Part X of the germanium crystal is doped with arsenic. Arsenic is a Group 15 (pentavalent) element, so doping with it provides extra electrons, making X an n-type semiconductor.

Part Y is doped with indium. Indium is a Group 13 (trivalent) element, which creates holes, making Y a p-type semiconductor.

In the given circuit diagram, the battery symbol has a longer line on the left and a shorter, thicker line on the right. This means the left side is the positive terminal and the right side is the negative terminal.

Since part X (n-type) is connected to the positive terminal and part Y (p-type) is connected to the negative terminal, the p-n junction is reverse biased.

Therefore, X is n-type, Y is p-type, and the junction is reverse biased.

Answer: X is n-type, Y is p-type and the junction is reverse biased