Semiconductor E...

The band diagrams of three semiconductors are given in the figure. From left to right they are respectively. 

Given: $$A$$ and $$B$$ are input terminals.
Logic $$1\, = \, > \, 5\, V$$
Logic $$0\, = \, < \, 1\, V$$
Which logic gate operation, the above circuit does?

A cube of germanium is placed between the poles of a magnet and a voltage is applied across opposite faces of the cube as shown in Figure. The magnetic field is directed vertical downward in the plane of the paper:
What effect will occur at the surface of the cube? 

The number of minority carriers crossing the junction of a diode depends primarily on the :

The logic operation carried out by the circuit below is that of

Current flowing in a Zener diode as shown in circuit: (Given diode is an ideal and $$V_z = 4V$$) 

The given truth table is

What is the voltage across an ideal p-n junction diode for shown circuit?

The combination of gates shown in the circuit is equivalent to

The charge in emitter current of a PNP transistor is 'x' and the corresponding change in the base current is 'y'. The $$\beta$$ factor of the transistor is