Electrical Machines In a DC generator, if P be the number of poles and N be the rpm of the rotor, then frequency of magnetic reversals will be PN/60. PN/120. PN/2. PN/3000. PN/60. PN/120. PN/2. PN/3000. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The speed of a motor falls from 1100 r.p.m at no-load to 1050 r.p.m at rated load. The speed regulation of motor is 2.56 %. 4.76%. 3.76%. 2.57 %. 2.56 %. 4.76%. 3.76%. 2.57 %. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Wave winding is employed in DC machine of low current and low voltage rating. low current and high voltage rating. high current and low voltage rating. high current and low voltage rating. low current and low voltage rating. low current and high voltage rating. high current and low voltage rating. high current and low voltage rating. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The DC generator runs at a speed of 1000 rpm and flux per pole is 0.2 Wb, number of poles are 2 the winding is wave wound and having 480 conductors. The critical speed is 1200 rpm. Then the generated emf ( Eg ) 1500 Volt. 0 Volt. 1600 Volt. 2000 Volt. 1500 Volt. 0 Volt. 1600 Volt. 2000 Volt. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Copper brushes in DC machine are used in both of above cases. None of these where low voltage and high currents are involved. where high voltage and low current. in both of above cases. None of these where low voltage and high currents are involved. where high voltage and low current. 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 Ω. The value of resistance which must be added to obtain rated torque at 1000 rpm is 5.7 Ω 6 Ω 2.2 Ω 1.9 Ω 5.7 Ω 6 Ω 2.2 Ω 1.9 Ω ANSWER DOWNLOAD EXAMIANS APP