1. Write a script file to do following problem The voltage difference Vab between points a and b in the Wheatstone bridge circuit is: Vab = R₂ + - R4 Calculate the voltage difference when V = 12 volts, R, 120 ohms, R₂ 100 ohms, R3 = 220 ohms, and R4 = 120 ohms. RA 2. Write a user-defined Matlab function to calculate the volume of sphere. 3. Write a MATLAB script file to plot the following signal: se'sin(t).( including axis and title)