# Tutor profile: Mir Asif A.

## Questions

### Subject: MATLAB

The following code prints all the numbers between 98 and 7 that are integer multiples of 7. What would be a suitable entry in the blank space? Line 1: clear all; Line 2: close all; Line 3: i = 98; Line 4: while i >= 7 Line 5: disp(i); Line 6: "Blank Space"; Line 7: end

i = i-7;

### Subject: Calculus

(a) What type of differential equations can be solved using the Method of Undetermined Coefficients? (b) What is a suitable particular solution function of a differential equation whose non-homogeneous part is: f(x) = exp(-x)+x^2+5?

(a) Method of Undetermined Coefficients can be used to solve the nonhomogeneous higher order differential equations. (b) yp(x) = Aexp(-x)+Bx^2+Cx+D.

### Subject: Electrical Engineering

What is the purpose of DC biasing in MOSFET amplifier circuit when the input is a small AC signal?

A MOSFET has three operating regions: Cut-off, Triode, and Saturation. Depending on the DC voltage applied to the drain, gate and emitter terminals of the MOSFET, one of these operating points can be selected. Since the MOSFET is being used as the active element of the amplifier circuit, it is important to make sure that due to the application of the AC input signal, the MOSFET does not go beyond its current operating region's threshold (for instance, going from triode region to cut-off). The biasing ensures that the amplifier can handle a sufficient amount of swing in the input voltage.