ACL2L7
What is the power factor of a circuit containing only XC?
0% 7Q3
What is the power factor of a series LC circuit?
0% 7Q4
Following questions are missing from this review....
7Q9&10
A LC circuit wherein I_C_ = 10 amps I_L_ = 5 amps The circuit is ( capacitive or inductive) ?
Capacitive 7Q22
Solve for E_C_ give I_T_ = 3A X_L_ = 80 ohms X_C_ = 35 ohms
E_C_ = I * X_C_ E_C_ = 3 * 35 E_C_ = 105 V 7Q6
Given a simple lc crkt E_T_ = 135 V X_L_ = 80 ohms X_C_ = 35 ohms Solve for I_T
E_L_ = E_T_ = E_C_ = 135 I_L_ = E_L_ / X_L_ I_L_ = 135 / 80 I_L_ = 1.6875 I_C_ = E_C_ / X_C_ I_C_ = 135 / 35 I_C_ = 3.8571428 I_T_ = I_C_ - I_C_ I_T_ = 3.86-1.69 = 2.17 A 7Q8
Solve for E_L give I_T_ = 3A X_L_ = 80 ohms X_C_ = 35 ohms
E_L_ = I * X_L_\ E_L_ = 3 * 80 E_L_ = 240 V 7Q5
Solve for E_T_ give I_T_ = 3A X_L_ = 80 ohms X_C_ = 35 ohms E_C_ = 105 V E_L_ =240 V
E_T_ = E_L_ - E_C_ E_T_ = 240 - 105 E_T_ = 135 V 7Q7
Solve for applied voltage given a singular circuit wherien E_C_ = 20 V E_L_ = 50 V
E_T_ = E_L_ = E_C_ E_T_ = 50 - 20 E_T_ = 30 V 7Q11
True or False as the frequency increases, the circuit approaches resonance. Given a LC circuit wherein E_app_ = 100 V X_C_ = 40 ohms X_L_ = 50 ohms
False 7Q31
Given a LC circuit wherein E_app_ = 100 V X_C_ = 40 ohms X_L_ = 50 ohms In the circuit shown, as the frequency increases, XC increases.
False 7Q33
True or False If a series circuit has an XL of 200 ohms and an XC of 250 ohms, the circuit is inductive.
False Note: Current is uniform in a series circuit; therefore, EC will be larger than EL, and the circuit will be capacitive. 7Q17
True or False In the circuit shown, the value of XC is greater than the value of XL. Given E_C_ = 20 V E_L_ = 50 V
False Note: Current is the same in a series circuit; since the inductor has the larger voltage drop, the value of XL must be larger than the value of XC. 7Q12
True or False A series LC circuit has an applied voltage of 100 volts. The voltage drop across XL or XC cannot be larger than 100 volts.
False Note: XL is 180° out-of-phase with XC, in a series circuit; the current will always be the reference. It follows that since the current IL is 90° out-of-phase with EL and IC is 90° out-of-phase with EC, then the voltages will be 180° out-of-phase with each other. Given this 180° out-of-phase relationship, the total voltage ET can be found by finding the difference between EL and EC. 7Q13
True or False In a parallel circuit, if XL equals 30 ohms and XC equals 40 ohms, the circuit will be capacitive.
False Note: What determines whether a parallel circuit is more capacitive or more inductive is not the value of the reactance but how much current flows through the component. In the parallel circuit described, the inductor would have the larger current; therefore, the circuit would be inductive. 7Q16
Solve for I_C_ given a LC circuit wherein E_app_ = 100 V X_C_ = 40 ohms X_L_ = 50 ohms
I_C_ = E / X_C_ I_C_ = 100 / 40 I_C_ = 2.5 A 7Q28
Solve for I_L_ given a LC circuit wherein E_app_ = 100 V X_C_ = 40 ohms X_L_ = 50 ohms
I_L_ = E / X_L I_L_ = 100 / 50 I_L_ = 2 A 7Q27
A LC circuit wherein I_C_ = 10 amps I_L_ = 5 amps The total current is ...
I_T_ = I_C_ - I_L_ I_T_ = 10 - 5 I_T_ = 5 A 7Q23
Solve for I_T_ given a LC circuit wherein E_app_ = 100 V X_C_ = 40 ohms X_L_ = 50 ohms I_C_ = 2.5 A I_L_ = 2 A
I_T_ = I_C_ = I_L_ I_T_ = 2.5 - 2 I_T_ = .5 A 7Q29
Given circuit A E_T_ = 100 V X_L_ = 400 ohms X_C_ = 300 ohms And circuit B E_T_ = 100 V X_L_ = 100 ohms Which has the larger current?
The currents are the same because the total reactance is the same in both circuits. Note: a. X_T_ = X_L_ - X_C_\ X_T_ = 400 - 300 X_T_ = 100 ohms b. X_T_ = X_L X_T_ = 100 ohms 7Q14
True or False Current in a series LC circuit is the same at all points.
True 7Q1
True or False In a series circuit, if XL equals 30 ohms and XC equals 40 ohms, the circuit will be capacitive.
True 7Q15
True of False The term resonance means that XL is equal to XC in a LC circuit.
True 7Q2
True or False The voltage across each branch is equal in a parallel LC circuit.
True 7Q25
In the circuit shown, as the frequency decreases, the circuit approaches resonance. Given a LC circuit wherein E_app_ = 100 V X_C_ = 40 ohms X_L_ = 50 ohms
True 7Q32
In the circuit shown, as the frequency increases, XL increases. Given a LC circuit wherein E_app_ = 100 V X_C_ = 40 ohms X_L_ = 50 ohms
True 7Q34
Complete the following statements by choosing increases, decreases, or stays the same. XC ? when frequency increases. XL increases when frequency ? . XC decreases when frequency ? . XL ? when frequency decreases.
XC DECREASES when frequency increases. XL increases when frequency INCREASES . XC decreases when frequency INCREASES . XL DECREASES when frequency decreases. 7Q20
Given a LC circuit wherein E_app_ = 6 V f = 750 Hz C = 470 nF L = 107 mH Find X_L_ X_C_ I_L_ I_C_ I_T_
X_L_ = 2 pi F * L X_L_ = 2 pi 750 * .107 X_L_ = 504.23 ohms X_C_ = 1 / 2/ pi / F / L X_C_ = 1 / 2/ pi / 750 / .107 X_C_ = 451.50 I_L_ = E_L_ / X_L_ I_L_ = 6 / 504.23 I_L_ = 11.90 mA I_C_ =E_C_ / X_C_ I_C_ = 6 / 451.5 I_C_ = 13.29 mA I_T_ = I_C_ - I_L_ I_T_ = 1.39 mA 7Q35
If the frequency was increased in the circuit shown, complete the following statements by choosing increase, decrease, or stay the same. Z would ? X_C_ would ? X_L_ would ? I would ?
Z would INCREASE X_C_ would DECREASE X_L_ would INCREASE I would DECREASE 7Q21
In an industrial plant, a circuit feeding a motor (an inductive load) is measured and found to have a current draw of 200 amperes. Since this is an inductive motor load, the power factor of the circuit can be improved by connecting a capacitor in parallel with the motor leads at the motor. A correctly sized capacitor is chosen to offset the effects of the induction. The result would be that line current would ? , and motor current would ? .
decrease / remain the same 7Q24 (has explanation one could look at)
If a series circuit has an XL of 200 ohms and an XC of 250 ohms, the current will ? the applied voltage.
lead 7Q18
In a parallel LC circuit, when XL equals XC, the impedance (Z ) is ? .
maximum 7Q30
In the circuit shown, which of the branch currents is in-phase with the applied voltage? Given A LC circuit wherein I_C_ = 10 amps I_L_ = 5 amps
neither branch Note: Both branch currents are 90° out-of-phase with the applied voltage; IC is leading and IL is lagging. 7Q26
When XL is nearly equal to XC in a series LC circuit, Z is near the ? and I is near the ?
zero maximum 7Q19
