Electrical Machines The direction of rotation of conductor of a DC motor can be determined by Lenz's law. Fleming's left hand rule. Fleming's right hand rule. Ampere law. Lenz's law. Fleming's left hand rule. Fleming's right hand rule. Ampere law. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines An 8 pole DC generator has 500 armature conductors and useful flux per pole of 0.065 Wb. What will be the emf generated if it is lap connected and runs at 1000 rpm. What must be the speed at which it is driven to produce the same emf if it is wave wound? 2166.67V, 270 rpm. 541.67V, 200 rpm. 541.67V, 250 rpm. 2166.67V, 230 rpm. 2166.67V, 270 rpm. 541.67V, 200 rpm. 541.67V, 250 rpm. 2166.67V, 230 rpm. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines What is the necessity of copper brushes in a dc motors? None of these. To convert alternating supply current to direct current. To increase the flux cutting by the rotor. To absorb the mechanical shocks produced during running condition. None of these. To convert alternating supply current to direct current. To increase the flux cutting by the rotor. To absorb the mechanical shocks produced during running condition. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Cogging and crawling are phenomena associated with any of the above. the former during starting and the latter at a fraction of its rated speed. cage induction machines and they are essentially the same. the former at a fraction of its rate speed and the latter during starting. any of the above. the former during starting and the latter at a fraction of its rated speed. cage induction machines and they are essentially the same. the former at a fraction of its rate speed and the latter during starting. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If residual magnetism of a shunt generator is destroyed accidentally it may be restored by connecting its shunt field in reverse. to an AC source. to earth. to a DC source. in reverse. to an AC source. to earth. to a DC source. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If the field circuit of a DC shunt motor is opened The speed of motor will be reduced. DC Shunt Motor The motor will attain dangerously high speed. The armature current will reduce. The speed of motor will be reduced. DC Shunt Motor The motor will attain dangerously high speed. The armature current will reduce. ANSWER DOWNLOAD EXAMIANS APP