Physics 1442 and 1444 Questions and problems Only

Transcription

1 Physics 1442 and 1444 Questions and problems Only U15Q1 To measure current using a digital multimeter the probes of the meter would be placed the component. ) in parallel with ) in series with C) adjacent to U15Q2 reading of 2.80 is displayed when measuring the resistance of a resistor. The range setting is set to 20k. What is the resistance of the resistor? ) 2800 ) 2.80 C) 5.60 D) 5600 U15Q3 waveform displayed on an oscilloscope is measured to have 6.3 vertical divisions and 4.7 horizontal divisions for one complete cycle. The Volt/div knob is set to 0.2 V/div and the Time/div knob to 0.5ms/div. Determine the peak to peak voltage of the waveform. ) 3.15 V ) 2.35 V C) 0.94 V D) 1.26 V U15P1 Determine the period, peak to peak voltage, rms voltage and frequency for the waveform in the below picture. The Time/div setting is 20 s and the Volt/div setting is 1V/div. period = peak to peak voltage = rms voltage = frequency = channel 1 channel 2

2 U16Q1 Electric field lines are equipotential lines ) tangent to ) perpendicular to C) the same as D) parallel to U16Q2 charge of 2 C is moved 3 cm along an equipotential surface that has a value of 4.56V. How much work was required to move this charge along the surface? )0 J ) 0.27 J C) 2.7 J D) 27 J U16Q3 The same charge is then moved a distance of 2 cm to another equipotential line that has a value of 3.21 V. How much work was required to move this charge? ) 0 J ) 0.27 J C) 2.7 J D) 27 J U16P1 The diagram below is a set of equipotential lines and surfaces. Complete the diagram by drawing in electric field lines and indicate where the field lines would be strongest and weakest. The surfaces are solid objects. Determine the field strength between given the points. 4.4V Points and d = 0.4 cm 10.4V 8.3V 6.7V 2.3V 12V E F 0V Points E and F d = 1.3 cm D C Points D and C d =4.4 cm

3 U17Q1 Three capacitors are connected in series they have values of 22 F, 33 F and 47 F. Determine the equivalent capacitance for the series circuit. ) 0.1 F ) 10 F C) 13 F D) 102 F U17Q2 If the capacitors in question U17Q1 are instead connected in parallel what would be the new equivalen capacitance. ) 0.1 F ) 10 F C) 13 F D) 102 F U17P1 Three capacitors are connected as shown in the circuit to the right. The capacitor values are 4.7 F 6.8 F and 3.3 F. Determine the minimum and maximum value that can be obtained between points and capacitors. for these

4 U18Q1 You measure the resistance of a normally 1500 ohm resistor and it measures to be infinite resistance. You conclude that the resistor is )open ) shorted C) the meter is broken U18Q2 You have the following three resistors connected in parallel. What is the equivalent resistance for this circuit? R 1 = 100, R 2 = 50, and R 3 = 250 U18Q3 ) 400 )2.5x10-3 C)3.4x10-2 D) 29 Kirchoff s voltage rule states that: ) The algebraic sum of all the resistance in a circuit is zero. ) The product of current and resistance is the voltage. C) The algebraic sum of the change in potential in a complete transversal of a loop in a circuit must be zero. D) The algebraic sum of the currents entering a junction equals the algebraic sum of the currents leaving the junction. U18P1 The voltage sources measures 5 volts. The table to its right indicates the no fault conditions and a faulty condition. R 1 = 2200, R 2 = 400, each individual resistor in R 3 = 250 V 1 I 1 I 2 R 1 R 2 C C I 3 R 3 V 2 no fault fault R C 2.28k 2.2k R 2.6k 2.6k R C V 1 5V 5V V 2 5V 5V I m I 2 10 m 11.8m I 3 Determine the fault in the circuit and then calculate the expected currents I 1, I 2 and I 3 for the faulty circuit.

5 U19Q1 Using three different voltmeters a group of students measured the same emf source. V 1 measured 1.52 v, V 2 measured 1.43 v and V 3 measured 1.35 v which voltmeter draws the most current from the emf source. U19Q2 ) V 1 ) V 2 C) V 3 D) they all draw the same amount of current standard cell with an emf of volts when placed in a potentiometer circuit was found to have an arbitrary length L std of n unknown cell is then placed in the circuit and a decade box set to 450 ohms is in parallel with the unknown cell. The circuit was adjusted to a null and the arbitrary length of the unknown cell with this load was found to be L unk = What is the terminal voltage V T? ) 0.70 v ) 1.45 v C) 1.42 v D) v U19P1 From the graph determine the emf of the cell and its internal resistance.

6 U20Q1 When subjected to a sinusoidal voltage, the reactance of a capacitor ) decreases as the frequency of the voltage source increases ) is not affected by the frequency of the voltage source C) increases as the frequency of the voltage source increases D) none of these U20Q2 The voltage across a inductor the current through the inductor. ) leads )lags C) is in phase with D) none of these U20Q3 The impedance of an inductor Z ind is determined to be 147 ohms at 2000 Hz and its DC resistance R L is 25 ohms. What would be the inductance of the inductor? ) 5.76 H ) 11 mh C) 144 H D) cannot be determined U20P1 Depicted below is an oscilloscope with two waveforms the darker line represents the current through an element and the lighter line represents the voltage across the element. Determine the phase angle between the voltage and current. What kind of element is it, resistor, capacitor or inductor?

7 U21Q1 What is the expected impedance, Z, of a series circuit that has a resistor of 150 ohms a capacitor of 0.47 F and an inductance of 68 mh with a dc resistance R L of 25 ohms and is subjected to a sinusoidal waveform with a frequency of 500 Hz. ) 1275 ohms ) 213 k ohms C) 261 ohms D) 496 ohms U21Q2 Using the values in question U21Q1 what would be the resonant frequency of this circuit ) 793 khz ) 890 Hz C) 1578 Hz D) cannot be determine from data given U21P1 RLC circuit resonates at 5000 Hz it has an inductor with a DC resistance of 65 ohms, a 0.47 F capacitor and a 330 ohm resistor. What is the value of the inductor? What would be the impedance of the circuit at 2400Hz? What is the expected phase angle between the input voltage and the current at 2400 Hz?

8 U22Q1 The law of refraction is represented by which equation below. ) i = r ) n 1 sin 1 = n 2 sin 2 C) sin c = 1/n 1 D) none of these U22Q2 You find that the critical angle for a piece of optical material is 54 what is the index of refraction for the material. U22Q3 ) 1.79 ) 1.49 C) 0.81 D) 1.24 The focal point from a concave mirror is the radius of curvature of the surface. ) twice ) equal to C) half D) one quarter U22P1 In the reflection and refraction lab a beam of white light is passed through a prism at an angle of 30 and separated into a spectrum. The red portion of the spectrum is measured to be at an angle of 52 and the blue at 55. What is the index of refraction for each color? n red = n blue = What is the velocity of the blue light as it passes through the prism. v blue prism = U22P2 Complete the expected path of the light rays. fp fp

9 U23Q1 When light passes through a double or multiple slit, at some distance away a pattern of dark and bright regions will occur on a blank screen. The dark regions are created by interference. ) destructive ) retroactive C) fractal D) constructive U23Q2 laser beam with a wavelength of 514.5nm passes through a single slit aperture. t a distance of 0.85 meters a diffraction pattern is seen on a screen. The distance from the center bright peak and the second order dark band is 1.25cm. What is the width of the single slit aperture? ) 0.4 m )0.7 m C) 0.07 mm D) 0.04 mm U23P1 The picture represents an interference pattern produced by a 670 nm laser passing through a multiple slit aperture. The aperture is 0.85 m from the detector. Determine the slit width and slit spacing for the aperture. slit width = slit spacing =

10 Solutions U15Q1 U15Q2 U15Q3 U15P1 U16Q1 U16Q2 U16Q3 U16P1 D period = 66 s Vpp = 4 V V rms = V freq = 15.15kHz C U19Q1 C U19Q2 U19P1 E 1.58V (y-intercept) r (slope) U20Q1 U20Q2 U20Q3 U20P1 inductor N= 3 n = 0.6 = (360 /3) * 0.6 = 72 U21Q1 U21Q2 U21P1 D L = 2.2mH 2400Hz = 409 = U22Q1 U22Q2 D U22Q3 C U22P1 n red = n blue = v blue = 1.9 x 10 8 m/s U22P2 E = 400V/m E CD = 52. V/m E EF = 177 V/m f p f p U17Q1 U17Q2 U17P1 D C min = 2.56 F C max = 3.67 F U18Q1 U18Q2 D U18Q3 C U18P1 one or more resistor(s) in R 3 is shorted I 1 = 2.2m, I 2 = 12.5m I 3 = 14.7m U23P1 U23Q2 C U23P1 slit width x = (8.5-5)cm/2 =1.75cm m = 2 a = 6.5x10-5 m = 0.65mm slit spacing y = ( )cm /2 = 0.625cm m=2 d = 1.82x10-4 m = mm