E5 Electrical Principles

49 questions in the pool. Your exam will include 4, one from each group below.

Practice E5 now

E5A

Resonance and Q: characteristics of resonant circuits; series and parallel resonance; definitions and effects of Q; half-power bandwidth

• E5A01What can cause the voltage across reactances in a series RLC circuit to be higher than the voltage applied to the entire circuit?
• E5A02What is the resonant frequency of an RLC circuit if R is 22 ohms, L is 50 microhenries, and C is 40 picofarads?
• E5A03What is the magnitude of the impedance of a series RLC circuit at resonance?
• E5A04What is the magnitude of the impedance of a parallel RLC circuit at resonance?
• E5A05What is the result of increasing the Q of an impedance-matching circuit?
• E5A06What is the magnitude of the circulating current within the components of a parallel LC circuit at resonance?
• E5A07What is the magnitude of the current at the input of a parallel RLC circuit at resonance?
• E5A08What is the phase relationship between the current through and the voltage across a series resonant circuit at resonance?
• E5A09How is the Q of an RLC parallel resonant circuit calculated?
• E5A10What is the resonant frequency of an RLC circuit if R is 33 ohms, L is 50 microhenries, and C is 10 picofarads?
• E5A11What is the half-power bandwidth of a resonant circuit that has a resonant frequency of 7.1 MHz and a Q of 150?
• E5A12What is the half-power bandwidth of a resonant circuit that has a resonant frequency of 3.7 MHz and a Q of 118?
• E5A13What is an effect of increasing Q in a series resonant circuit?

E5B

Time constants and phase relationships: RL and RC time constants; phase angle in reactive circuits and components; admittance and susceptance

• E5B01What is the term for the time required for the capacitor in an RC circuit to be charged to 63.2% of the applied voltage or to discharge to 36.8% of its initial voltage?
• E5B02What letter is commonly used to represent susceptance?
• E5B03How is impedance in polar form converted to an equivalent admittance?
• E5B04What is the time constant of a circuit having two 220-microfarad capacitors and two 1-megohm resistors, all in parallel?
• E5B05What is the effect on the magnitude of pure reactance when it is converted to susceptance?
• E5B06What is susceptance?
• E5B07What is the phase angle between the voltage across and the current through a series RLC circuit if XC is 500 ohms, R is 1 kilohm, and XL is 250 ohms?
• E5B08What is the phase angle between the voltage across and the current through a series RLC circuit if XC is 300 ohms, R is 100 ohms, and XL is 100 ohms?
• E5B09What is the relationship between the AC current through a capacitor and the voltage across a capacitor?
• E5B10What is the relationship between the AC current through an inductor and the voltage across an inductor?
• E5B11What is the phase angle between the voltage across and the current through a series RLC circuit if XC is 25 ohms, R is 100 ohms, and XL is 75 ohms?
• E5B12What is admittance?

E5C

Coordinate systems and phasors in electronics: rectangular coordinates; polar coordinates; phasors; logarithmic axes

• E5C01Which of the following represents pure capacitive reactance of 100 ohms in rectangular notation?
• E5C02How are impedances described in polar coordinates?
• E5C03Which of the following represents a pure inductive reactance in polar coordinates?
• E5C04What type of Y-axis scale is most often used for graphs of circuit frequency response?
• E5C05What kind of diagram is used to show the phase relationship between impedances at a given frequency?
• E5C06What does the impedance 50 - j25 ohms represent?
• E5C07Where is the impedance of a pure resistance plotted on rectangular coordinates?
• E5C08What coordinate system is often used to display the phase angle of a circuit containing resistance, inductive, and/or capacitive reactance?
• E5C09When using rectangular coordinates to graph the impedance of a circuit, what do the axes represent?
• E5C10Which point on Figure E5-1 best represents the impedance of a series circuit consisting of a 400-ohm resistor and a 38-picofarad capacitor at 14 MHz?
• E5C11Which point in Figure E5-1 best represents the impedance of a series circuit consisting of a 300-ohm resistor and an 18-microhenry inductor at 3.505 MHz?
• E5C12Which point on Figure E5-1 best represents the impedance of a series circuit consisting of a 300-ohm resistor and a 19-picofarad capacitor at 21.200 MHz?

E5D

RF effects in components and circuits: skin effect; real and reactive power; electrical length of conductors

• E5D01What is the result of conductor skin effect?
• E5D02Why is it important to keep lead lengths short for components used in circuits for VHF and above?
• E5D03What is the phase relationship between current and voltage for reactive power?
• E5D04Why are short connections used at microwave frequencies?
• E5D05What parasitic characteristic causes electrolytic capacitors to be unsuitable for use at RF?
• E5D06What parasitic characteristic creates an inductor's self-resonance?
• E5D07What combines to create the self-resonance of a component?
• E5D08What is the primary cause of loss in film capacitors at RF?
• E5D09What happens to reactive power in ideal inductors and capacitors?
• E5D10As a conductor's diameter increases, what is the effect on its electrical length?
• E5D11How much real power is consumed in a circuit consisting of a 100-ohm resistor in series with a 100-ohm inductive reactance drawing 1 ampere?
• E5D12What is reactive power?