a) Current must flow through the coil to produce magnetic field b) The magnetic field has the same strength with or without current c) Current must flow but no voltage need be applied across the coil d) The coil must have high resistance for minimum coil current Ans: (a)
a) Without any additional magnetic field b) By moving the conductor from a weaker field towards stronger field c) By moving the conductor from stronger field towards weaker field d) By producing the motion by not rotation Ans: (c)
a) Magnetic flux moving across a conductor b) Magnetic flux moving across a dielectric c) An insulated wire free from any external magnetic field d) A bare wire moving parallel to an external magnetic field Ans: (a)
a) 1/5 amp b) 500 ma c) 10 amps d) 20 amps e) 5 amps Ans: (e)
a) Primary voltage b) Primary current c) Secondary voltage d) Secondary current Ans: (b)
a) Ferrites have low resistance b) Ferrites have high resistance c) Ferrites have low permeability d) Ferrites have high hysteresis Ans: (b)
a) D.c. shunt motor b) Reluctance motor c) Single phase induction motor (split phase start or induction run motor) d) Synchronous motor Ans: (c)
a) Extreme hot weather conditions b) Poor door seal at gasket c) Defective motor d) Defective thermostat Ans: (d)
a) 180° C b) 105° C c) 120° C d) 155° C Ans: (b)
a) Class A insulation b) Class Y insulation c) Class H insulation d) Class B insulation Ans: (b)
a) True b) False Ans: (b)
a) Thumb rule b) Lenz’s law c) Kirchhoff’s law d) Faraday’s law Ans: (b)
a) A magnetic field b) Movably placed loops conductors (turns) c) Lump conductors d) (a) and (b) both Ans: (d)
a) Counter-clockwise around the conductor b) Clockwise around the conductor c) Around the conductor d) Outside the conductor Ans: (b)
a) Left-hand rule b) Right-hand rule c) Corkscrew rule d) Lenz’s law Ans: (c)