Electrical Engineering 1

Question 1

Sinusoidal Voltage across resistor

Answer 1

v_R=I_P Rsin(ωt)

Question 2

Sinusoidal Voltage across inductor

Answer 2

v_L=ωLI_P cos(ωt)

Question 3

Sinusoidal Voltage across capacitor

Answer 3

v_C=-I_P/ωC cos(ωt)

Question 4

CIVIL

Answer 4

In C, I leads V; V leads I in L

Question 5

Voltage Relationships with impedance

Answer 5

V=IX_L
V=IX_C
V=IR

Question 6

Equations for impedance

Answer 6

X_L=ωL

X_C=1/ωC

Question 7

Equation for ω

Answer 7

2πf

Question 8

Total Impedance

Answer 8

Z=Z_R+Z_L+Z_C

Question 9

Complex Impedance Definitions

Answer 9

Z_R=R
Z_L=jωL
Z_C=1/jωC
Z=R+j(ωL-1/ωC)

Question 10

Power gain (dB)

Answer 10

P gain=10log_10(P2/P1)

Question 11

Voltage gain, cut off frequency and cut off ω in High Pass RC circuit

Answer 11

v_o/v_i=1/(1-j(1/ωCR))=1/(1-j(f_c/f))
ω_c=1/CR=1/T
f_c=1/2πCR

Question 12

Voltage gain, cut off frequency and cut off ω in Low Pass RC circuit

Answer 12

v_o/v_i=1/(1+jωCR)=1/(1+j(f/f_c))
ω_c=1/CR=1/T
f_c=1/2πCR

Question 13

Voltage gain, cut off frequency and cut off ω in Low Pass RL circuit

Answer 13

v_o/v_i=1/(1+jω(L/R))
w_c=R/L=1/T
f_c=ω_c/2π

Question 14

Voltage gain, cut off frequency and cut off ω in High Pass RL circuit

Answer 14

v_o/v_i=1/(1-j(R/ωl))
w_c=R/L=1/T
f_c=ω_c/2π

Question 15

Resonance Equations

Answer 15

w_o=1/sqrt(LC)

f_o=1/2πsqrt(LC)

Question 16

Quality Factor

Answer 16

Q=V_L/V_R=V_C/V_R=(1/R)sqrt(L/C)=f_o/B

Question 17

Bandwidth

Answer 17

B=R/2πL

Question 18

Impedance in a rejector circuit

Answer 18

Z=1/((1/R)+j(ωC-1/(ωL)))

Question 19

Dissipation and Resonant Frequency

Answer 19

γ=R/L

ω_o^2=1/(CL)

Question 20

Average Power

Answer 20

P_R=(1/2)V_PI_P
P_C=0
P_L=0

Question 21

Complex Power, Active Power and Reactive Power

Answer 21

S=(1/2)VI
P=V_rmsI_rmscosφ
Q=V_rmsI_rmssinφ

Question 22

Line to line to line to neutral voltages

Answer 22

Vln=Vll/sqrt3