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 2.2 ohms. 1.9 ohms. 5.7 ohms. 6 ohms. 2.2 ohms. 1.9 ohms. 5.7 ohms. 6 ohms. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines To get the speed of DC motor more than normal without wastage of electrical energy _____________ is used. rheostatic control. Ward Leonard control. none of above. any of above method. rheostatic control. Ward Leonard control. none of above. any of above method. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Induction motors normally use cast aluminium rotor because aluminium is cheaper in cost. easy to cast owing to its low melting point and is easily available. of low resistivity. lighter in weight. cheaper in cost. easy to cast owing to its low melting point and is easily available. of low resistivity. lighter in weight. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In case of IM the torque is directly proportional to slip2. inversely proportional to slip. directly proportional to slip. inversely proportional to √slip. directly proportional to slip2. inversely proportional to slip. directly proportional to slip. inversely proportional to √slip. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A DC shunt generator builds up to a voltage of 220 V at no load while running at its rated speed. If the speed of the generator is raised by 25% kepping the circuit conditions unaltered, then the Voltage to which the machine would build up will increase to 1.25 times 220 V increase to a value greater than 1.25 times 220 V not change and remain at 220 V increase to value lying between 220 V and 1.25 times 220 V increase to 1.25 times 220 V increase to a value greater than 1.25 times 220 V not change and remain at 220 V increase to value lying between 220 V and 1.25 times 220 V ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The demagnetising component of armature reaction in a DC generator results in sparking trouble. reduces generator emf. reduces inter poles flux density. increases armature speed. results in sparking trouble. reduces generator emf. reduces inter poles flux density. increases armature speed. ANSWER DOWNLOAD EXAMIANS APP
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