Which one of the following represents forward biased circuit?

In the following figure, the diodes which are forward biased, are (I) (II) (III) (IV). Choose the correct option from the given ones:

An n-p-n transistor is connected in the common base configuration in a given amplifier. A load resistance of $800\, \Omega$ is connected in the collector circuit and the voltage drop across it is $0.8\text{ V}$. If the current amplification factor is $0.96$ and the input resistance of the circuit is $192\, \Omega$, the voltage gain and the power gain of the amplifier will respectively be:

In a common-emitter transistor amplifier, the audio signal voltage across the collector is $3\text{ V}$. The resistance of the collector is $3\text{ k}\Omega$. If the current gain is $100$ and the base resistance is $2\text{ k}\Omega$, the voltage and power gain of the amplifier are:

If in a p-n junction, a square input signal of $10 \text{ V}$ is applied as shown, then the output across $R_L$ will be:

For transistor action: (a) the base, emitter and collector regions should have similar size and doping concentrations. (b) the base region must be very thin and lightly doped. (c) the emitter-base junction is forward biased and the base-collector junction is reverse biased. (d) both the emitter-base junction as well as the base-collector junction are forward biased. Which of the following pairs of statements is correct?

A p-n photodiode is fabricated from a semiconductor with a band gap of $2.5 \text{ eV}$. It can detect a signal of wavelength:

Which one of the following statements is false?

Pure $\text{Si}$ at $500\text{ K}$ has an equal number of electron ($n_e$) and hole ($n_h$) concentration of $1.5 \times 10^{16} \text{ m}^{-3}$. Doping by indium increases the hole concentration $n_h$ to $4.5 \times 10^{22} \text{ m}^{-3}$. The doped semiconductor is of: