Download App

14. Semicondutor electronics — Physics STD 12 Science — Question

CBSE BoardEnglish MediumSTD 12 SciencePhysics14. Semicondutor electronics1 Mark
MCQ
The collector current in a common base amplifier using $n-p-n$ transistor is $24\; mA$. If $80 \%$ of the electrons released by the emitter is accepted by the collector, then the base current is numerically
  • A
    $6\,mA$ and leaving the base
  • B
    $3\,mA$ and leaving the base
  • ✓
    $6\,mA$ and entering the base
  • D
    $3\,mA$ and entering the base
✓

Answer

Correct option: C.
$6\,mA$ and entering the base
c
$I _C=24\,mA$

$\text { and } I _{ E }=\frac{ I _{ C }}{\alpha}$

$I _{ E }=\frac{24 mA }{0.8}=30\,mA$

$\therefore I _{ B }= I _{ E }- I _C$

$=6\,mA \text { (into the base) }$

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Explore more

More "M.C.Q (1 Marks)" from 14. Semicondutor electronics→14. Semicondutor electronics — all question types→Physics STD 12 Science question papers→CBSE Board STD 12 Science question papers→CBSE Board question paper generator→

Similar questions

In Young's double slit experiment, if the two slits are illuminated with separate sources, no interference pattern is observed because
→
A source of sound moves towards an observer.
→
Cutoff wavelength of $X-$rays coming from a Coolidge tube depends on the:
→
A ray of light incident normally on an isosceles right angled prism travels as shown in the figure. The least value of the refractive index of the prism must be
→
An electron (charge = $1.6 \times {10^{ - 19}}$ $coulomb$) is accelerated through a potential of $1,00,000$ $volts$. The energy required by the electron is
→
A deviation of $2^{\circ}$ is produced in the yellow ray when prism of crown and flint glass are achromatically combined. Taking dispersive powers of crown and flint glass are $0.02$ and $0.03$ respectively and refractive index for yellow light for these glasses are $1.5$ and $1.6$ respectively. The refracting angles for crown glass prism will be $........\,^{\circ}$ (in degree) (Round off to the Nearest Integer)
→
Current in the circuit is wattless, if
→
Determine the electric field strength vector if the potential of this field depends on $x, y$ coordinates as $V=10$ axy
→
The resistance of a rectangular block of copper of dimensions $2 \,mm \times 2 \,mm \times 5 \,m$ between two square faces is $0.02 \,\Omega$. What is the resistivity of copper?
→
X-rays of $\lambda=1 \mathrm{~A}^0$ have frequency
→