Home
Learn
Plan & Focus
Community
Pricing
Play & Compete
Free Resources

Log in Join Free

by JEE Master

Ask. Share. Learn. Grow Together. India's all-in-one community for JEE Main & JEE Advanced aspirants.

Explore

Learn
Plan & Focus
Community
Play & Compete
Free Resources

Resources

JEE Main PYQs
JEE Advanced PYQs
Formula Sheets
NCERT Mapping
Mock Analysis

Support

Help Center
Privacy Policy
Terms of Use
Contact Us

© 2026 PadhoNa. All rights reserved.

Formula Sheets / Physics

Chapter 31

Semiconductors

Revise with flashcards Download this chapter (PDF) All Physics formulas (PDF)

Semiconductors and the p-n junction Diode circuits and rectifiers Transistors Logic gates

Semiconductors and the p-n junction

$n_{e} n_{h} = n_{i}^{2};$ n-type: $n_{e} ≫ n_{h};$ p-type: $n_{h} ≫ n_{e}$
Conductivity
$σ = e (n_{e} μ_{e} + n_{h} μ_{h})$

Diode circuits and rectifiers

Ripple frequency
half-wave: $f;$ full-wave: $2 f$
Efficiency
half-wave $40.6%;$ full-wave $81.2%$
Zener
reverse biased beyond breakdown: voltage stays at $V_{z}$

Transistors

$I_{E} = I_{B} + I_{C},$ $α = \frac{I _{C}}{I _{E}},$ $β = \frac{I _{C}}{I _{B}} = \frac{α}{1 - α}$
CE amplifier
$A_{v} = - β \frac{R _{L}}{R _{in}},$ $A_{p} = β A_{v}$

Logic gates

AND $Y = A B;$ OR $Y = A + B;$ NOT $Y = \overset{ˉ}{A};$ NAND $\overline{A B};$ NOR $\overline{A + B}$
XOR
$Y = A \overset{ˉ}{B} + \overset{ˉ}{A} B$
De Morgan
$\overline{A + B} = \overset{ˉ}{A} \overset{ˉ}{B},$ $\overline{A B} = \overset{ˉ}{A} + \overset{ˉ}{B}$

Nuclear Physics Communication Systems