If a semiconductor photodiode can detect a photon with a maximum wavelength of , then its band gap energy (in eV) is :
Planck's constant
Speed of light
Both the diodes used in the circuit shown are assumed to be ideal and have negligible resistance when these are forward biased. Built-in potential in each diode is 0.7V. For the input voltages shown in the figure, the voltage (in Volts) at a point A is ______________
The output characteristics of a transistor is shown in the figure. When $V_{C E}$ is 10 V and $I_C=4.0 \mathrm{~mA}$. then value of $\beta_{a c}$ is _______.