Deepakkumar Yadav
Deepakkumar Yadav Separate source voltage withstand test : (Power frequency) Q. Explain with neat sketch power frequency high voltage test on transformer. This test is made with the help of single phase a.c. voltage of sinusoidal waveforms as far as possible and at a frequency not less than 80% of rated frequency. At the end of the … Read more
Different Types of Primary and Secondary Connections of Transformer Q. State the suitability of following type of 3-phase transformer: (i) Y-Y (ii) Y-∆ (iii) ∆– ∆ (iv) ∆ – Y Q. Draw the connection diagram, symbol and phasor diagram of phasor group-1 (New phase displacement) of transformer connection (i) Y-Y (ii) ∆–∆ (iii) ∆-Z Q. Explain Zig-Zag connection of transformer. Types of Primary … Read more
When any one-phase of a 3-phase synchronous motor is short-circuited, the motor A) Will overheat in the spot B) Will fail to pull into step C) Will refuse to start D) Will not come upto speed Correct Answer is C) Will refuse to start Explanation Failure of a … Read more
The A.C. armature winding of an alternator is A) Delta Star connected Generally B) Delta Connected C) Star Delta Connected D) Always Star connected Correct answer is D) Always Star connected Explanation Alternators are connected primarily in the star to achieve the following motives: More economical:- The phase voltages in star connection are 57.7 % … Read more
Electric Circuit Compared with Water Circuit An electric circuit is the path in which the electric current flows. The flow of electricity in a wire is actually the simultaneous motion of countless free electrons in one direction. It is often compared with the flow of a liquid like water. Electricity can then be said to … Read more
Wire Selection for House wiring Instagram :- https://bit.ly/2sh9sHE Get More Great Videos – 🔔Subscribe → https://goo.gl/agWVY1 How to Make Electrical Extension Board, Step by Step (In Hindi) :- https://youtu.be/en4gid3BOJY How To Make An Electric Extension Board, Inner Wiring Connection ( In Hindi ) :- https://youtu.be/eqmo2FpaXcc What is Transformer Interview Questions, Electrical Transformer :- https://youtu.be/w0MTIbBJp0Y Why … Read more
The electrons in the outermost orbit of an atom are usually not securely bound to the nucleus and therefore may fly off the atom (Figure A) and move into an outer orbit of another atom. These relatively free electrons normally move at random in all directions. However, when an electrical pressure (voltage) is applied across … Read more
Electron Theory The basis of our understanding of electricity is the electron theory. This theory states that all matter, that is, everything that occupies space and has weight, is composed of tiny invisible units called atoms. Atoms in turn are subdivided into still smaller particles called protons, neutrons, and electrons. The protons and neutrons make … Read more
The mechanical power is developed by a DC motor is maximum when (A) Back emf is equal to twice of applied voltage. (B) Back emf is equal to half of applied voltage. (C) Back emf is equal to applied voltage. (D) None of above. Answer :- For motor, Eb = Vt − IaRa Mechanical power … Read more
The concept of V/f control of inverters driving induction motors results in (A) Constant torque operation (B) Speed reversal (C) Reduced magnetic loss (D) Harmonic elimination Answer So, if we maintain the flux is a constant value, then torque also will be a constant value. Correct Answer is (A) Constant Torque Operation.