Electronics and Communication Engineering - Exam Questions Papers

Find 'X' in the circuit below :

f₁(A, B, C, D) = Σ(6, 7, 13, 14);
f₂(A, B, C, D) = Σ(3, 6, 7);
f₃(A, B, C, D) = Σ(5, 6, 7, 14, 15)

Suppose that the modulating signal is m(t) = 2cos (2pf_mt) and the carrier signal is x_C(t) = A_C cos(2pf_ct), which one of the following is a conventional AM signal without over modulation?

What are the values of E_max and E_min displayed on the oscilloscope, when a 1 kV P-P carries is modulated to 50%?

Consider the common emitter amplifier shown below with the following circuit parameters: β = 100, g_m = 0.3861 A/V, r₀ = ∞ r_p = 259 Ω, R_s = 1 kΩ, R_B = 93 kΩ, R_C = 250 Ω, R_L = 1 kW, C₁ = ∞ and C₂ = 4.7mF.

The resistance seen by the source Vs is

As the temperature increases the mobility of electrons __________ .