21 3-42.   Which of the following switches is unacceptable because of the momentary position? 1.    C 2.    F 3.    G 4.    H 3-43.   Which of the following switches has the wrong locked position? 1.    B 2.    D 3.    F 4.    G 3-44.   Which of the following switches has an unacceptable voltage rating? 1.    B 2.    D 3.    E 4.    F 3-45.   Which of the following switches has an unacceptable current rating? 1.    B 2.    C 3.    D 4.    F 3-46.   When you perform preventive maintenance on a switch, which of the following items should be checked? 1.    The terminals for corrosion 2.    The physical condition of the switch 3.    The switch operation for smooth and correct operation 4.    All of the above 3-47.   A solenoid is based upon which of the following principles? 1.    A bimetallic strip bends when it is heated 2.    A thermocouple produces a current when heated 3.    A coil attracts a soft iron core when current flows in the coil 4.    A soft iron core moving in a magnetic field creates a current 3-48.   A solenoid is commonly used in which of the following devices? 1.    A fuel quantity indicating system 2.    A shipboard lighting system 3.    A sound-powered telephone system 4.    A starter for a motor vehicle 3-49.   If a solenoid is not operating properly, which of the following items need NOT be checked? 1.    Coil 2.    Armature 3.    Plunger 4.    Energizing voltage _______________________________________ IN ANSWERING QUESTIONS 3-50 THROUGH 3-54, MATCH THE DEVICE(S) LISTED IN COLUMN B TO THE STATEMENTS IN COLUMN A.  THE DEVICES IN COLUMN B MAY BE USED MORE THAN ONCE. A.  STATEMENTS B.  DEVICES 3-50. An electromagnetic device 1. A switch only 3-51. A device with a movable plunger 2. A solenoid only 3-52. A device with a fixed core 3. A relay only 3-53. A device classified as power or control 4. A relay and a solenoid 3-54. A device containing an armature _______________________________________