Semiconductor Electronics Quiz-2

An a.c voltage of peak value 10 V is connected in series with a silicon diode a load resistance of $100\,\Omega$. The forward resistance of the diode to $20\,\Omega$. The peak output voltage across the load resistance will be:

The semiconductor used for fabrication of visible LEDs must at least have a band gap of

Intensity of light emitted by LED depends on

Colour of the light emitted by LED depends on

If x, y and z are lengths of the emitter, base, and collector of a transistor then:

In a junction transistor, the current gain in CB configuration is 0.99. If input resistance is $2k\,\Omega$ and load connected to collector is $10 k\,\Omega$, then voltage gain in CE configuration will be:

In a transistor the current amplification ‘$\alpha$’ is 0.9. The change in collector current when base current changes by 4 mA is

Is an n–p–n transistor $10^{12}$ electrons enter emitter in 80 $\mu s$. The current gain α of transistor is 0.95. The number of electrons flowing in the base expressed as a percentage of electrons entering emitter is

The transfer ratio $\beta$ of a transistor is 50. The input resistance of the transistor when used in the common emitter configuration is $1k \,\Omega$. The value of collector current for a peak value of input a.c voltage of 0.01 is

A signal of 30 mV is applied to a common emitter transistor amplifier circuit. Due tothis the change in base current and the change in the collector current are $20\,\mu A$ and 2 mA respectively. The load resistance is $15\,k\Omega.$. The transconductance of the transistor is