Electrical Machines A voltmeter gives 120 oscillations per minute when connected to the rotor of an induction motor. The frequency is 50Hz. The slip of the motor is 4% 2% 25% 5% 4% 2% 25% 5% ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 240 V DC series motor takes 40 A when giving its rated output at 1500 rpm. Its resistance is 0.3 ohms. The value of resistance which must be added to obtain rated torque at 1000 rpm is 5.7 ohms. 2.2 ohms. 1.9 ohms. 6 ohms. 5.7 ohms. 2.2 ohms. 1.9 ohms. 6 ohms. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If B is flux density, l the length of the conductor and v the velocity of the conductor, then emf is given by Bl2v2. Blv2. Blv. Bl2v. Bl2v2. Blv2. Blv. Bl2v. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The results of a slip test for determining direct axis (Xd) and quadrature axis (Xq) reactances of a star connected salient pole alternator are given below Phase values: Vmax = 108 V ; Vmin = 96 V Imax = 12 A ; Imin = 10 A Hence the two reactances will be Xd = 9.6Ω and Xq = 9Ω Xd = 10.8Ω and Xq = 8Ω Xd = 9Ω and Xq = 9.6Ω Xd = 8Ω and Xq = 10.8Ω Xd = 9.6Ω and Xq = 9Ω Xd = 10.8Ω and Xq = 8Ω Xd = 9Ω and Xq = 9.6Ω Xd = 8Ω and Xq = 10.8Ω ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a seperately excited DC Motor if field current is increased, it will Increase acceleration duration. Increase speed Reduce starting torque. Reduce armature heating. Increase acceleration duration. Increase speed Reduce starting torque. Reduce armature heating. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Flashing the field of DC generator means neutralising residual magnetism. creating residual magnetism by a DC source. making the magnetic losses forces parallel. increasing flux density by adding extra turns of winding. neutralising residual magnetism. creating residual magnetism by a DC source. making the magnetic losses forces parallel. increasing flux density by adding extra turns of winding. ANSWER DOWNLOAD EXAMIANS APP
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