Semiconductor Electronics NEET MCQs

Semiconductor Electronics NEET MCQs Formulae

• Conductivity: sigma = 1 / rho, and J = sigma E
• Intrinsic semiconductor: n_e = n_h = n_i
• Mass action law: n_e n_h = n_i^2
• Semiconductor conductivity: sigma = e(n_e mu_e + n_h mu_h)
• Intrinsic conductivity: sigma_i = n_i e(mu_e + mu_h)
• Energy gap from wavelength: E_g(eV) = 1240 / lambda(nm)
• Diode equation: I = I_0(e^(V / eta V_T) - 1), where V_T = kT / e
• Half-wave rectifier: I_dc = I_m / pi, I_rms = I_m / 2, efficiency = 40.6%
• Full-wave rectifier: I_dc = 2I_m / pi, I_rms = I_m / sqrt(2), efficiency = 81.2%
• Ripple factor: gamma_half = 1.21, gamma_full = 0.482
• Form factor: FF_half = 1.57, FF_full = 1.11
• Zener regulator: R_s = (V_in - V_Z) / I, and I = I_L + I_Z
• Transistor currents: I_E = I_C + I_B
• Current gains: alpha = I_C / I_E, beta = I_C / I_B
• Alpha-beta relation: beta = alpha / (1 - alpha), alpha = beta / (1 + beta)
• CE voltage gain: A_v = beta R_C / R_in
• Power gain: A_p = A_v A_i
• Gain in decibel: G_dB = 10 log10(P_out / P_in) = 20 log10(V_out / V_in)
• Logic NOT: Y = A'
• Logic AND / OR: AND: Y = A.B, OR: Y = A + B
• Universal gates: NAND: Y = (A.B)', NOR: Y = (A + B)'
• XOR and XNOR: XOR: Y = A'B + AB', XNOR: Y = AB + A'B'