# Uosef Alshamali_2.docx - ECET201 u2013 U3 u2013 VD...

• 7

This preview shows page 1 - 4 out of 7 pages.

ECET201 – U3 – VD Question 1: Solve the following problem 1- Find the equivalent capacitance in the following circuit in a step by step solution (without drawing): (10 points) Equivalent capacitance: = ( 20 mF + 20 µF )/ ¿ ( 100 μF + 10 mF )/ ¿ 10 μF = 20.02 mF / ¿ 10.1 mF / ¿ 0.01 mF = ( 1 / 20.02 + 1 / 10.1 + 1 / 0.01 ) 1 = 9.985 μF 1
Question 2: Solve the following RC circuit: (25-points) For the circuit shown, for t ≥ 0 given that Vc (0) = 25V. Find the following: a) The equivalent resistance (5 Points) = R 1// R 2 + Xc = ( 100 k × 120 k )/( 100 k + 120 k )= 54.545 kΩ Capacitive reactance Using frequency of 60Hz X c = 1/ jωc = 1 / j × 120 π× ( 20 × 10 6 )= j 132.63 Equivalent resistance = 54,545 j 132.63 b) Vc(t) (10 Points) V c ( t )= Vmsinωt = 25sin ( 120 πt ) c) Ic(t) (10 Points) d) ic ( t )= Imsinωt = 25sin ( 120 πt ) 2
Question 3: Solve the following complex operation (10 Points) Find the following operation in RECTANGULAR form with a step-by-step solution : M = ( 43 + j 88 ) × ( 70 j 210 ) HINT: CONVERT TO POLAR BEFOR SOLVING. Converting to polar coordinates: 43 + j 88 r 1 = ( 43 2 + 88 2 )= 97.14 θ 1 = tan 1 ( 88 / 43 ) = 63.96 ° θ 1 = 97.14 63.96 ° 70 j 210 r 1 = ( 70 2 + 210 2 )= 221.36 θ 2 = tan 1 ( 210 / 70 ) = 71.57 ° θ 2 = 221.36 71.57 ° 108.43 ° Multiplication = r 1 r 2 { cos (
• • • 