Physics Alternating Current Level: High School
Oscillator
A 1.00 microF capacitor is charged by a 40 volt power supply . The fully charged capacitor is then discharged through a 10.0 mH inductor .a) Find the frequency of oscillation in this LC circuit .
b) Find the maximum current in the resulting oscillation
c) Assuming perfect capacitors and inductors , how much energy was initially stored in the capacitor ?
d) What is the value of the maximum energy stored in the inductor ?
e) A 50.0 ohm resistor is placed in series with the inductor and capacitor and the capacitor is again charge by the 40 volt power supply . When the capacitor is then discharged through the inductor and resistor , what is the new frequency of the damped oscillation ?
f) What percentage change in frequency did the resistor in part (e) produce ?
Physics Alternating Current Level: High School
A series RCL circuit contains a 106 ohm resistor , a 3.3 micro-Farad capacitor , and a 31.0 mH inductor . The generator has a frequency of 609 Hz and an rms voltage of 35.0 V . Find the following .a) the phase angle between the current and the voltage of the generator .
b) the rms voltage across each circuit element .
Physics Alternating Current Level: High School
At what frequency will a generator with an rms voltage of 504 V produce an rms current of 7.50 mA in a 0.0150 micro-F capacitor ?
Physics Alternating Current Level: High School
A 105 microF capacitor is connected to an ac generator with an rms voltage of 20.0 V and a frequency of 100.0 Hz . What is the rms current in this circuit ?
Physics Alternating Current Level: High School
RL-Circuits- 6.0 V battery , 37-mH inductor , four 50 ohms resistors .a) Find the characteristic time for this circuit
b) What is the current supplied by this battery two characteristic time intervals after closing the switch ?
Physics Alternating Current Level: High School
If two branches of a 440 v parallel circuit have the impedances of z = 2-j and z = 1+3j , what is the true power in the circuit , approximately .
Physics Alternating Current Level: High School
An RLC circuit consists of a 15 microF capacitor , a 78 ohm resistor and a 90 mH inductor. The oscillator is set for 560 Hz output a sinusoidal voltage of 105 V. Determine :a) The current flowing in the circuit .
b) The voltage drop across each of the circuit elements .
Physics Alternating Current Level: High School
An L-C circuit consists of an inductor with L = 0.800 H and a capacitor with C = 6.00 x 10^-4F . The initial charge on the capacitor is 5.00 micro C , and the initial current in the inductor is zero .a) What is the maximum voltage across the capacitor ?
b) What is the minimum current in the inductor ?
c) What is the maximum energy stored in the inductor ?
d) When the current in the inductor has half its maximum value , what is the charge on the capacitor and what is the energy stored in the inductor ?
Physics Alternating Current Level: High School
Alternating Currents
A resistor with a resistance of 500 ohm and a capacitor with a capacitance of 2.00 micro F are connected in parallel to an ac generator that supplies a rms voltage of 240 V at an angular frequency of 377 rad . s-1 . Finda) The current amplitude in the resistor .
b) The current amplitude in the capacitor
c) The phase angle (sketch the phasor diagram for the current phasors)
d) The amplitude of the current through the generator .
Physics Alternating Current Level: High School
When a 1500-W hair dryer is in use , the current passing through the dryer may be represented as I = (17.7A) sin (120 pai t ) . What is the rms current for this circuit ?a) 17.7 A
b) 12.5 A
c) 85.7 A
d) 25.0 A
e) 8.85 A
Physics Alternating Current Level: High School
The current in a circuit at time t seconds is given by i = 80 sin (200 pi t – 0.548) . Find .a) the amplitude , periodic time , frequency and phase angle in degrees stating , with reference to 80 sin 200 pi t, whether it leads or lags .
b) the value of the current when t = 0 ,
c) the value of the current when t = 12 ms ,
d) the time when the current first reaches 50 A .
Physics Alternating Current Level: High School
A television station broadcasts at a frequency of 86 MHz . The circuit contains an inductor with an inductance L = 1.2 x 10^-6 H and a variable capacitance C . Determine the value of C that allows this television station to be turned in .a. 2.9 x 10^-12 F
b. 5.8 x 10^-12 F
c. 1.8 x 10^-11 F
d. 3.6 x 10^-11 F
e. 1.1 x 10^-10 F
Physics Alternating Current Level: High School
Semi conductors
Which one of the following statements concerning diodes is false ?a. A diode is fabricated by forming junctions between one n-type and two p-type semi-conductors or one p-type and two n-type semi-conductors .
b. At an n-p junction in a diode that is not connected to a battery , an electric field exists across the junction.
c. A battery can be connected to a diode so that a continual flow of charge results.
d. A diode connected to an ac source allows current to flow only in one direction.
e. Holes move in a diode under a forward-bias condition .
Physics Alternating Current Level: High School
Which one of the following statement best explains why semiconductors in transistors are doped ? a. Doping makes the charge carries mobile . b. Doping makes the charge carriers immobile. c. Doping make the semi-conducting materials non-conducting. d. Doing changes the conductive properties of the semi-conductors. e. Doping converts the semi-conducting materials into a metallic material like copper.Physics Alternating Current Level: High School
The graph at “click here” shows the impedance as a function of frequency for a series RCL circuit . At what frequency does the capacitor make the larges contribution ?a. f1
b. f2
c.f3
d. f1 or f3
e. f1 or f2 or f3
