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 1.9 ohms. 6 ohms. 5.7 ohms. 2.2 ohms. 1.9 ohms. 6 ohms. 5.7 ohms. 2.2 ohms. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A synchronous machine has P number of poles, find the relation between electrical angular momentum (ωe) and mechanical angular momentum (ωm)? ωe = P/2*ωm ωe = ωm ωe = P*ωm ωe = 2/P*ωm ωe = P/2*ωm ωe = ωm ωe = P*ωm ωe = 2/P*ωm ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In alternator, the rotary part is none of these. core. armature. magnetic field poles. none of these. core. armature. magnetic field poles. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 240 V, dc shunt motor draws 15 A while supplying the rated load at a speed of 80 rad/s. The armature resistance is 0.5 W and the field winding resistance is 80 W. The external resistance to be added in the armature circuit to limit the armature current to 125% of its rated value is 31.9 Ω 15.1 Ω 15.9 Ω 31.1 Ω 31.9 Ω 15.1 Ω 15.9 Ω 31.1 Ω ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If peak value of phase mmf is F max , then peak value of the rotating field caused by three phase is (3/2)Fmax. (1/2)Fmax. 3Fmax. Fmax. (3/2)Fmax. (1/2)Fmax. 3Fmax. Fmax. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Two mechanically coupled alternators deliver power at 50 Hz and 60 Hz respectively. Highest speed of alternator is 3000 rpm. 3600 rpm. 600 rpm. 500 rpm. 3000 rpm. 3600 rpm. 600 rpm. 500 rpm. ANSWER DOWNLOAD EXAMIANS APP