Description : A synchronous motor maintains synchronism with the rotating field because _____________. A. field strength varies directly with rotor slip B. DC current applied to the rotor coils causes the rotor ... the flux created by the excitation current D. the stator flux rotates in the opposite direction
Last Answer : Answer: B
Description : Find total number coils in a spring having square and ground ends. Deflection in the spring is 6mm when load of 1100N is applied. Modulus of rigidity is 81370N/mm². Wire diameter and pitch circle diameter are 10mm and 50mm respectively. a) 7 b) 6 c) 5 d) 4
Last Answer : a) 7
Description : If two coils are wound on a single iron core, what will a change in current in one coil cause in the other coil?
Last Answer : A change in inductance.
Last Answer : In a Weston frequency meter, the magnetic axes of the two fixed coils are perpendicular.
Description : What is the device, which depends on the action of a movalbe permanent magnet, in aligning itself in the resultant field produced by a fixed permanent magnet or current- carrying coils whose axes are displaced by a fixed angle?
Last Answer : moving-magnet instrument
Last Answer : In a Weston synchronoscope, the fixed coils are connected across incoming alternator.
Description : Rotating the plane of polarization of a wavefront by passing it through a ferrite device is called what?
Last Answer : . Faraday rotation.
Description : What is the purpose of rotating the gimbal assembly in a gyro using a mercury erection system?
Last Answer : Applies torque at the proper point for correct precession.
Description : Why is no emf induced in a rotating coil when it passes through the neutral plane?
Last Answer : No flux lines are cut.
Description : What is the main advantage of the rotating field alternator?
Last Answer : Output voltage is taken directly from the armature (not through brushes or slip rings).
Description : The speed of the rotor is always somewhat less than the speed of the rotating field. What is the difference called?
Last Answer : Slip.
Description : What determines the number of field poles required to establish a rotating magnetic field in a multiphase motor stator?
Last Answer : The number of phases in the applied voltage.
Description : Capability of rotating objects around a fixed axis is called?
Last Answer : Torque
Description : Is it necessary for an axle to be ______ with respect to rotating element? a) Stationary b) Moving c) Moving or stationary d) fixed
Last Answer : c) Moving or stationary
Description : When a mass is rotating in a plane about a fixed point, its angular momentum is directed along: (1) the tangent to the orbit (2) a line perpendicular to the plane of rotation (3) the line making an angle of 45° to the plane of rotation (4) the radius
Last Answer : (2) a line perpendicular to the plane of rotation
Description : Discharge switches are often located on hand-driven meggers. The purpose of these switches is to discharge capacitive charges stored in the _____________. A. megger hand generator B. megger movement coils C. tested equipment while conducting test D. tested equipment after testing
Last Answer : Answer: D
Description : When troubleshooting motor controllers, a shorted relay or contactor coil is often indicated by _______________. A. a resistance reading of 'infinity' on an ohmmeter B. charred insulation and/or a blown ... of the coil's leads to ground D. a higher-than-normal voltage reading across the winding
Description : Why are the ends of the deflection plates bent outward?
Last Answer : To permit wide-angle deflection of the bea
Description : The horizontal-deflection plates are used to produce what function?
Last Answer : Time and/or frequency relationships.
Description : The vertical-deflection plates are used to reproduce what function?
Last Answer : Amplitude.
Description : Is the deflection angle greater when the beam is moving faster or slower?
Last Answer : Slower beam.
Description : Is the deflection angle greater with higher or lower potential on the plates?
Last Answer : Higher potential.
Last Answer : To permit wide-angle deflection of the beam.
Description : What term is used to describe the reciprocal of deflection sensitivity of a scope?
Last Answer : Deflection factor.
Description : What effect do longer deflection plates have on the electron beam?
Last Answer : A greater deflection angle.
Description : What type of deflection is preferred for a crt electron beam?
Last Answer : . Electromagnetic.
Description : . A full-scale deflection on an ohmmeter scale indicates what resistance between the leads?
Last Answer : Zero.
Description : A full-scale deflection on an ohmmeter scale indicates what resistance between the leads?
Description : (True or False) The larger the current required to produce full-scale deflection of the meter coil, the better the sensitivity of the meter.
Last Answer : False.
Description : Which among the following is the value of static deflection (δ) for a fixed beam with central point load? A ( Wl 3 ) /(192 EI) B ( Wl 2 ) /(192 EI) C (Wl 3 ) /(384 EI) D None of the above
Last Answer : A ( Wl 3 ) /(192 EI)
Description : δ = (W a 2 b 2 ) / (3 EIL) is the value of deflection for ______ A. simply supported beam which has central point load B. simply supported beam which has eccentric point load C. simply supported beam which has U.D.L. point load per unit length D. fixed beam which has central point load
Last Answer : B. simply supported beam which has eccentric point load
Description : Which among the following is the value of static deflection (δ) for a fixed beam with central point load? a. (Wl 3 ) /(192 EI) b. (Wl 2 ) /(192 EI) c. (Wl 3 ) /(384 EI)
Last Answer : a. (Wl 3 ) /(192 EI)
Description : δ = (W a 2 b 2 ) / (3 EIl) is the value of deflection for ______ a. simply supported beam which has central point load b. simply supported beam which has eccentric point load c. simply supported beam which has U.D.L. point load per unit length d. fixed beam which has central point load
Last Answer : b. simply supported beam which has eccentric point load
Description : The maximum deflection of (A) A simply supported beam carrying a uniformly increasing load from either end and having the apex at the mid span is WL3 /60EI (B) A fixed ended beam ... ended beam carrying a concentrated load at the mid span is WL3 /192EI (D) All the above
Last Answer : (D) All the above
Description : Which of the following theorem can be used for deflection in fixed beams a. Mohr’s first theorem b. Mohr’s second theorem c. Mohr’s third theorem d.Mohr’s fourth theorem
Last Answer : b. Mohr’s second theorem
Description : For the same span and loads fixed beam in comparison with simply supported beams has a. lesser value of maximum deflection b. more value of maximum deflecction c.twice the value of maximum deflecction d.same value of maximum deflecction
Last Answer : a. lesser value of maximum deflection
Description : Deflection of an off centre loaded fixed beam is a.Wa3 b3/ 3L3EI b.Wa3b3/ 8L3EI c.Wa3b3/ 192L3EI d.Wa3b3/ 384L3EI
Last Answer : a.Wa3 b3/ 3L3EI
Description : For a fixed beam with UDL, maximum deflection is a.wL4/48EI b.wL4/192EI c. wL4/384EI d.wL3/192EI
Last Answer : c. wL4/384EI
Description : For a fixed beam with midpoint load point deflection for x
Last Answer : c. (Px2/48EI)(3L-4x)
Description : For a fixed beam with midpoint load point, maximum deflection at the centre is a.PL3/ 192EI b.PL2/ 48EI c.PL4/ 192EI d.PL3/ 48EI
Last Answer : a.PL3/ 192EI
Description : A cantilever of length 3m carries a point load of 60 KN at a distance of 2m from the fixed end.If E= 2×105 and I=108, what is the deflection at the free end?. a.7 mm b.14 mm c.26 mm d.52 mm.
Last Answer : b.14 mm
Description : Maximum deflection in a cantilever beam with UDL w over the entire length will be a. At the free end. b. At the fixed end. c. At the centre d. None.
Last Answer : a. At the free end.
Description : Maximum deflection in a cantilever beam with W at the free end will be a. at the free end. b.at the fixed end. c.at the centre d.None.
Last Answer : a. at the free end.
Description : What three types of storage elements most often are used in modulators?
Last Answer : Capacitor, artificial transmission line, or pulse-forming network.
Description : Why is the ac induction motor used more often than other types?
Last Answer : They are simple and inexpensive to make.