Avariable attenuator can be implemented by using a 4? port 90◦ hybrid coupler by terminating ports 2 and 3 with equal but adjustable loads. (a) show that the transmission coefficient (i. e., global s21) between the input and output is given as t = jγ. also show that the input port is matched for all values of γ.

What difference(s) did you notice using a pneumatic circuit over hydraulic circuit. explain why the pneumatic piston stumbles when it hits an obstacle.

Asolid cylinder is concentric with a straight pipe. the cylinder is 0.5 m long and has an outside diameter of 8 cm. the pipe has an inside diameter of 8.5 cm. the annulus between the cylinder ad the pipe contains stationary oil. the oil has a specific gravity of 0.92 and a kinematic viscosity of 5.57 x 10-4 m2/s. most nearly, what is the force needed to move the cylinder along the pipe at a constant velocity of 1 m/s?

Prove the equivalence between the two statements of the 2nd law of thermodynamics (i. e., a violation of one statement leads to the violatio the other statement)