Prepare for the APPSC Inspector of Factories (Electrical) recruitment examination with official previous years' solved question papers across Electrical Circuits & Machinery, Power Generation, Transmission & Distribution, Industrial Substation Design, CEA (Measures Relating to Safety & Electric Supply) Regulations 2010, Indian Electricity Rules 1956, Factories Act 1948 (Electrical Safety Provisions), Earthing Practices (IS 3043), Flameproof Apparatus for Hazardous Explosive Atmospheres (IS/IEC 60079), Protection Relays, and Industrial Fire Safety Systems.
Marking pattern: +1.00 positive, -0.33 (1/3rd) negative marking (Official APPSC Technical CBT Scheme; 150 Questions, 150 Marks).
In a 3 phase induction motor, if supply voltage and supply frequency are reduced by the same degree, then under maximum torque conditions:
The following method is preferred for speed control of cage rotor induction motor:
For 4% drop in supply voltage, the torque of an induction motor decreases by:
In a 3 phase Induction motor, a deep bar rotor is used for obtaining:
In a polyphase single cage induction motor (SCIM) increased starting torque can be obtained by:
(i) increasing the frequency of operation
(ii) using deep bar rotors
(iii) increasing the number of poles
(iv) using a double cage rotor
From these, the correct answer is:
In a polyphase IM using double-cage, the rotor current flows mainly through the:
(i) upper cage at starting
(ii) lower cage at starting
(iii) upper cage at normal speed
(iv) lower cage at normal speed
From the above the correct answer is:
In a double-cage IM the inner cage and outer cage have respectively:
Speed control in a 3-phase IM by pole changing method is applicable to:
Line voltage control for the speed regulation of a 3-phase SCIM is not so important because this method offers:
For a poly-phase SRIM when low speed is obtained by rotor resistance control, then:
In a 3-phase IM speeds higher than synchronous speeds can be obtained by:
The rotor output of a 3-phase induction motor is 15 kW and the slip is 4%, then the rotor copper loss is:
In a 3-phase Induction motor, plugging requires that:
D.C. dynamic braking is obtained by:
A single phase induction motor is provided with a 3-phase slip ring rotor connected to a starting resistance. This motor would:
The low power factor of a 3-phase induction motor at low load results from:
In a polyphase IM, the rotor slots are skewed by:
(i) one slot-pitch
(ii) two slot-pitch
(iii) one harmonic pole pitch
(iv) two harmonic pole pitch
From the above the correct answer is:
Crawling in a 3-phase IM may be due to:
(i) harmonic induction torque
(ii) harmonic synchronous torque
(iii) broken end-ring
(iv) broken rotor bar
From the above the correct answer is:
A single phase induction motor is labelled 1 and a 3-phase induction motor is labelled 2. When slip is 0 (zero):
In various types of split phase induction motors the starting torques produced are in the following descending order :
In a capacitor-split motor if $C_{1}$ is the capacitance required for the best starting torque and $C_{2}$ for the best running performance, then:
In capacitor start and run 1-phase induction motors starting capacitor $C_{1}$ and permanent capacitor $C_{2}$ are as under:
The direction of rotation of a 1-phase induction motor can be reversed by:
In a 1-phase induction motor, maximum starting torque may be obtained with auxiliary winding connected in series with:
The most suitable motor for a tape-recorder will be: