The maximum short circuit current occurs due to which fault: Single line to ground fault Line to line fault Three phase bolted fault Double line to ground fault Correct answer: 3. Three phase bolted fault
Condensers in thermal power plants are used to condense: Water to ice Steam to water Hydrogen to liquid gas Carbon dioxide to air Correct answer: 2. Steam to water
Which of following power plant is most suitable to supply the peak load of power system: Thermal Diesel Nuclear None of these Correct answer: 2. Diesel
As one moves from consumers to power station, what is effect on the diversity factor of the power system: Diversity factor increases Diversity factor decreases It remains the same None of these Correct answer: 2. Diversity factor decreases
If maximum demand on a power plant is equal to plant capacity, then the value of the load factor is: Less than plant capacity factor More than plant capacity factor Equal to plant capacity factor None of these Correct answer: 3. Equal to plant capacity factor
Flat rate tariff is charged on the basis of which factor: Maximum demand Connected load Units consumed 1 & 3 Correct answer: 3. Units consumed
Transformer coupling in transistor amplifiers provides high power gain because: Transformer is a static device A transformer can step up voltages Impedance matching can be achieved None of these Correct answer: 3. Impedance matching can be achieved
1 dB corresponds to change in voltage or current level of: 1% 12% 25% 32.5% Correct answer: 2. 12% Voltage or current gain in dB = 20 log10 (V2/V1) 1 = 20 log10 (V2/V1) V2/V1 = 1.12 = (1.12 – 1)/1 * 100% = 12% So a 1 dB corresponds to change in voltage or … Read more
The all day efficiency of transformer is also known as: Current efficiency Power efficiency Energy efficiency None of these Correct answer: 3. Energy efficiency
A 30 ohms resistive load is to impedance matched to transformer to a source having an internal resistance of 3000 ohms. The ratio of primary to secondary turns of transformer should be: 0.1 1 10 1000 Correct answer: 3. 10 SolutionL (N1/N2)2 = Zp/Zs (N1/N2)2 = (3000/30) (N1/N2)2 = 100 N1/N2 = 10