260. For a synchronous phase modifier the load angle is
A. 0?
B. 25?
C.300
D. none of these
261. The insulation resistance of a cable of langth 10 km is 1 MO, its resistance for 50 km length will be
A. 1 M
B. 5 M
C. 0.2 M
D. none of these
262. Three insulating materials with breakdown strengths of 250 kV/cm, 200 kV/cm, 150 kV/cm and permittivities of 2.5, 3.0 and 3.5 are used in a single core cable. If the factor of safety for the materials is 5, the location of the materials with respect to the core of the cable will be
A. 2.5,3.0,3.5
B. 3.0,2.5,3.5
C. 3.5,3.0,2.5
D. 3.5, 2.5,3.0
263. Three insulating materials with same maximum working stress and permittvities 2.5, 3.0, 4.0 are used in a single core cable. The location of the materials with respect to the core of the cable will be
A. 2.5,3.0,4.0
B. 3.0,2.5,4.0
C. 4.0,3.0,2.5
D. 4.0, 2.5,3.0
264. Select the correct statement
A. The negative and zero sequence voltages are maximum at the fault point and decrease towards the neutral.
B. The negative and zero sequence voltages are minimum at the fault point and increase towards the neutral.
C. The negative sequence is maximum and zero sequence minimum at the fault point and decrease and increase respectively towards the neutral.
D. None of these
265. For measuring positive, negative and zero sequence voltages in a system, the reference is taken as
A. neutral of the system only.
B. ground only.
C. for zero sequence neutral and for positive and negative the ground.
D. none of these
266. Percent bias for a generator protection lies between
A. 5 to 40
B. 40 to 45
C. 45 to 20
D. none of these
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