12.1 A class A emitter follower, biased using the circuitshown in Fig. 12.3, uses Vcc=10V, R = RL=\kQ., withall transistors (including Q3) identical. Assume V££ = 0.7 V, VC£sat = 0.3 V, and ft to be very large. For linear operation, what are the upper and lower limits of output voltage, andthe corresponding inputs? How do these values change if theemitter-base junction area of Q3 is made twice as big as thatof S2? Half as big?

Amixture of slurry and mud is to be pumped through a horizontal pipe of diameter 500 mm. the fluid behaves as a bingham plastic with a yield stress of 30 pa and viscosity 0.04 pa. s. describe the effects of the shear stress through a transverse section of the pipe by plotting the variation in shear stress and velocity profile: (i) just before the slurry starts to move (ii) as the slurry flows when the pressure gradient is double that in part (i)