List of top Physics Questions on Semiconductor electronics: materials, devices and simple circuits asked in KCET

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?
In which of the following figures, diode is reverse biased?
An n-type and p-type semiconductor can be obtained by respectively doping pure silicon with