Physics NCERT Exemplar Solutions Class 12th Chapter Fourteen

Diode conducts current only in one direction.

From Truth table $Y=\overline{AB}$ .

$\mathcal{l}=2\pi r$

$\Rightarrow 314cm=2*3.14r$

$\Rightarrow r=\raisebox{1ex}{$1$}\!\left/ \!\raisebox{-1ex}{$2$}\right.m=0.5m$

$\mu =iA$

$=14*\pi r^2$

$=14^2*\frac{22}{7}*\frac{1}{4}=11$

D₁ → forward biased

D₂ → Reversed biased

So, current will flow through only  D₁

$l=\frac{\left(1-0.6\right)v}{\left(60+40\right)\Omega }=\frac{0.4}{100}$                

= 4 * 10^-3 A

= 4mA

A = 8 cm

T = 6 sec

q = 60° from A to B

During reaching the point its maximum amplitude from point (A)

$\theta =60°=\frac{{\pi }^C}{3}$

$\theta =\omega t$                

$\frac{\pi }{3}=\frac{2\pi }{6}t$                              

t = 1 sec

For Transistor

to act as a switch → Saturation & cut – off state

to act as an amplifier → Active Region

$x=sin\pi \left(t+\frac{1}{3}\right)$

$v=\frac{dx}{dt}=cos\left[\pi \left(t+\frac{1}{3}\right)\right]*\pi$

$=cos\left(\pi +\frac{\pi }{3}\right)*\pi$

$=-cos\frac{\pi }{3}*\left(\pi \right)$

$=-\frac{\pi }{2}=-1.57m/sec$              

Speed = 157 cm/sec

This is a Multiple Choice Questions as classified in NCERT Exemplar

Answer- (a, d)

Explanation- In reverse biasing, the minority charge carriers will be accelerated due to reverse biasing, which on striking with atoms cause ionization resulting secondary electrons and thus more number of charge carriers.

When doping concentration is large, there will be large number of ions in the depletion

region, which will give rise to a strong electric field.

This is a Multiple Choice Questions as classified in NCERT Exemplar

Answer- a, c, d

Explanation-ripple factor is inversely proportional to R_L, C  and frequency. so to reduce ripple factor all these should be increase.

This is a Multiple Choice Questions as classified in NCERT Exemplar

Answer-b, d

Explanation- During regulation action of a Zener diode, the current through the Rs changes and resistance offered by the Zener changes. The current through the Zener changes but the voltage across the Zener remains constant.