In a common base mode of a transistor, the collector current is $$5.488$$ $$mA$$ for an emitter current of $$5.60mA.$$ The value of the base current amplification factor $$\left( \beta \right)$$ will be

If the ratio of the concentration of electrons to that of holes in a semiconductor is $${7 \over 5}$$ and the ratio of currents is $${7 \over 4},$$ then what is the ratio of their drift velocities?

A solid which is not transparent to visible light and whose conductivity increases with temperature is formed by

If the lattice constant of this semiconductor is decreased, then which of the following is correct?