a) Tf/Tmax =2a/(a2 + s2) b) Tf/Tmax =2/(a2 + s2) c) Tf/Tmax =2as/(a2 + s2) d) Tf/Tmax =a/(a2 + s2) Ans: (c)
Where s is the slip and a = R2/X2 = (Resistance of the rotor)/(Resistance of the rotor)
a) Ts/Tmax = 2a/(1 + a2 ) b) Ts/Tmax = 2a/(S2 + a2 ) c) Ts/Tmax = 2/(1 + s2 ) d) Ts/Tmax = 2a/(S2 + 1) Ans: (a)
a) True b) False Ans: (a)
a) Star connected only b) Delta connected only c) (a) and (b) both d) None of the above Ans: (c)
a) K × torque with direct switching b) K/ torque with direct switching c) K2 × torque with direct switching d) K2/torque with direct switching Ans: (c)
Where tapping of transformation ratio K is used in case of auto-transformer.
a) 70% b) 71% c) 71.5% d) 72.2% Ans: (d)
When the short circuit current on normal voltage is 4 times the full load and full load slip is 30%.
a) 57% b) 56.5% c) 86.6% d) 58% approximately Ans: (d)
a) True b) False Ans: (b)
a) True b) False Ans: (a)
a) Improper design of the machine b) Low voltage supply c) High Loads d) Harmonics developed in the motor Ans: (d)
a) True b) False Ans: (b)
a) True b) False Ans: (b)
a) True b) False Ans: (a)
a) In parallel b) In series parallel c) In series d) In parallel with stator Ans: (a)
a) True b) False Ans: (b)
 Multiple Choice Question (MCQ) of Electronics page-17:241. Which of the following statement is true? a) The saturation voltage VCF of silicon transistor is more than germanium transistor. b) The saturation voltage VCE for germanium transistor is more than silicon transistor. c) The saturation voltage VCE for silicon transistor is same as that for germanium. d) The saturation voltage VCE for silicon transistor is lower than germanium transistor. |
Multiple Choice Question (MCQ) of Electronics page-16:226. Which of the following statement is correct? a) Inner electrons are always present in the semiconductor. b) Bound electrons are always present in the semiconductor. c) Free electrons are always present in the semiconductor. d) Inner and bound electrons are always present in the semiconductor. |
Multiple Choice Question (MCQ) of Electronics page-15:211. The materials whose electrical conductivity is usually less than 1 × 106 mho/m are a) Semiconductors b) Conductors c) Insulators d) Alloys |
Multiple Choice Question (MCQ) of Electronics page-14:196. In which of the following device the base resistors are not added in the package but added externally? a) UJT b) CUJT c) PUT d) None of the above |
Multiple Choice Question (MCQ) of Electronics page-13:181. The conduction in JEFT is always by the a) Majority carriers b) Minority carriers c) Holes d) Electrons e) Holes and electrons simultaneously |