16 2-40.   It is difficult to measure resistances less than 1 ohm with a bridge because of which of the following factors? 1.  Contact resistance is present between the resistor being measured and the binding posts of the bridge 2.  Excessive supply voltage is required to excite the galvanometer 3.  The frequency of the excitation source creates excessive skin currents in the resistor under test 4.  The excitation voltage causes low- value resistors to heat excessively 2-41.   What type of bridge is recommended for measuring resistances less than 1 ohm? 1.  Wheatstone bridge 2.  Schering bridge 3.  Maxwell bridge 4.  Kelvin bridge 2-42.   When using resistance-ratio bridges to measure capacitance, inductance, or resistance, you should compare the unknown component with which of the following components? 1.  A capacitor 2.  An inductor 3.  A resistor 4.  A similar standard 2-43.   A Hay bridge measures unknown inductances by comparing them with which, if any, of the following components? 1.  A standard inductor 2.  A standard resistor 3.  A standard capacitor 4.  None of the above 2-44.   What is the advantage of using a Maxwell bridge over a Hay bridge? 1.  The Maxwell bridge can measure greater range of inductances 2.  The Maxwell bridge can measure much smaller resistances 3.  The Maxwell bridge can provide a greater accuracy over a smaller range 4.  The Maxwell bridge can measure inductances having a high Q 2-45.   Which of the following pieces of test equipment measure(s) the magnitude and phase angle of an unknown impedance? 1.  The vector bridge 2.  The impedance-angle meter 3.  Both 1 and 2 above 4.  The Hay bridge 2-46.   Maximum transfer of rf energy between transmitter/receiver and antenna will occur under which of the following circumstances? 1.  When the transmitter or receiver is properly matched to the antenna 2.  When the receiver is tuned one sideband above the transmitter 3.  When the transmitter is tuned one sideband above the receiver 4.  Both 2 and 3 above 2-47.   Rf impedance bridge measurements require the use of which of the following pieces of equipment? 1.  An ac power source, a detector, and a Wheatstone bridge 2.  An rf signal generator, an oscilloscope, and a power supply 3.  An rf signal generator, an rf bridge, and a detector 4.  A Schering bridge, a detector, and an rf power supply