9 1-54.   You are measuring the speed of a fan blade by using a stroboscopic tachometer.  Setting the flash at a rate 5 rpm SLOWER than the fan speed will cause the blades to appear to move (a) in what relative direction and (b) at what speed? 1.  (a) Forward (b)   5 rpm 2.  (a) Forward (b) 10 rpm 3.  (a) Backward (b) 10 rpm 4.  (a) Backward (b)   5 rpm 1-55.   The flashing rate of a strobotac is controlled by which of the following circuits? 1.  An electronic pulse generator 2.  A frequency divider 3.  A power supply 4.  An amplifier 1-56.   The flashing rate of the strobotron tube affects its life expectancy. What is the range (in hours) of life expectancy of the strobotron tube? 1.    15 to   24 2.    25 to   49 3.    50 to   99 4.  100 to 250 1-57.   The vibrating-reed frequency meter is a delicate instrument and should not be subjected to vibrations, such as those associated with motor-generators or their associated control panels. 1.  True 2.  False 1-58.   When using the vibrating-reed frequency meter, you take the reading in which of the following ways? 1.  Read the digital readout 2.  Read the dial indication 3.  Read the mechanical setting 4.  Read the reed that vibrates the most 1-59.   Bandpass filters and band reject filters are tuned circuits that either pass or reject specific frequencies. In these filters, (a) what type offers very high impedance to currents at its resonant frequency, and (b) what type offers a very low impedance to currents at its resonant frequency? 1.  (a) Parallel-tuned     (b) series-tuned 2.  (a) Parallel-tuned     (b) parallel-tuned 3.  (a) Series-tuned (b) parallel-tuned 4.  (a) Series-tuned (b) series-tuned 1-60.   When you are zero beating an unknown frequency with a frequency provided by a calibrated, high-precision oscillator within a heterodyne frequency meter, what will be the indication when the two frequencies are matched? 1.  One dot of light on the screen will be superimposed on the other 2.  One vertical line on the screen will be superimposed on the other 3.  The two tones in the headset will achieve the same pitch, at which time a series of clicks will begin 4.  The tone in the headset will decrease in pitch and be replaced by clicks that will become slow or nonexistent THIS SPACE LEFT BLANK INTENTIONALLY.