1. Open circuit test in a transformer is performed with
- rated transformer voltage
- rated transformer current
- direct current
- high frequency supply
2. In performing the short circuit test on a transformer
- high voltage side is usually short circuited
- low voltage side is usually short circuited
- any side is usually short circuited
- none of the above
3. In a transformer
- both open and short circuit tests are performed on LV side
- Open circuit test is conducted in HV side and short circuit test on LV side
- Open circuit test is performed on LV side and short circuit test on HV side
- both Open and short circuit tests are performed on HV side
4. Power factor of a ac circuit is defined as
- PF=cosθ
- PF=R/|z|
- PF=P(real)/P(app)
- all of the above
5. Power factor PF is
- PF α 1/I
- PF α I
- PF α I^2
- PF α 1/I^2
6. A transmission as well as distribution system of electric power is known as good if
- High value of voltage regulation and efficiency
- low value of voltage regulation and high value of efficiency
- Good power factor and lower voltage regulation
- none of the above
7. Charcoal, common salt are used in earthing due to following reasons:
- They increases the conductivity of the soil
- They increases the contact area of the earth
- They maintains moisture and increase earth resistance
- none of the above
8. Voltage source has
- smaller resistance than load R
- Higher internal resistance than load R
- Internal resistance is not present i.e zero in all cases
- very small internal resistance
9. Material subjected to rapid reversal of magnetism should have
- high permeability and low hysteresis loss
- Large B-H loop area
- large coercivity and high retentivity
- low permeability and large coercivity
10. Area of hysteresis loop represents
- copper loss
- eddy current loss
- hysteresis loop
11. Silicon content in steel reduces
- hysteresis loop
- eddy current loss
- copper loss