Power System Protection

Air gap of magnetic path ✘ Number of ampere-turns ✘ Adjustable back up stop ✘ None of these ✔

Low ✘ Medium ✘ High ✘ Independent of the change in air gap ✔

0.2 to 0.3

✘

0.3 to 0.4

✘

0.4 to 0.6

✘

0.6 to 1.0

✔

Impedance ✘ Current difference ✘ Voltage difference ✘ None of these ✔

Stability, reliability ✘ Speed sensitivity ✘ Selectivity, adequacy ✘ None of these ✔

Current during abnormal condition ✘ Voltage during abnormal condition ✘ Both (a) and (b) simultaneously ✘ Constantly the electrical quantities which differ during normal and abnormal conditions ✔

Low ✘ High ✘ Medium ✘ Very high ✔

Arcing time ✘ Opening time ✘ Closing time ✘ None of these ✔

Current difference ✘ Voltage difference ✘ Impedance difference ✘ Distance between two CT ✔

Line-to-line fault ✘ Line-to-line circuit ✘ Dead short circuit ✘ Both (a) and (b) occurring simultaneously ✔