A. high in case of D.C. traction than in the case of AC. traction
B. low in case of D.C. traction than in the case of AC. traction
C. equal in both AC. and D.C. traction
D. any of the above
Related Mcqs:
- Due to which of the following co-efficient of adhesion improves ?
A. Rust on the rails
B. Dust on the rails
C. Sand on the rails
D. All of the above - Co-efficient of adhesion reduces due to the presence of which of the following ?
A. Sand on rails
B. Dew on rails
C. Oil on the rails
D. both B. and C. - The value of co-efficient of adhesion will be high when rails are_________________?
A. greased
B. wet
C. sprayed with oil
D. cleaned with sand - If the co-efficient of adhesion on dry rails is 0.26, which of the following could be the value for wet rails ?
A. 0.3
B. 0.26
C. 0.225
D. 0.16 - The normal value of adhesion friction is______________?
A. 0.12
B. 0.25
C. 0.40
D. 0.75 - When a bogie negotiates a curve, reduction in adhesion occurs resulting in sliding. Thus sliding is acute when_______________?
A. wheel base of axles is more
B. degree of curvature is more
C. both A. and B.
D. none of the above - For three-phase induction motors which of the following is the least efficient method of speed control ?
A. Cascade control
B. Pole changing
C. Rheostat control
D. Combination of cascade and pole changing - The value of stability factor for a base resistor bias is________________?
A. RB (ß+1)
B. (ß+1)RC
C. (ß+1)
D. 1-ß - A debouncing circuit is________________?
A. an astable MV
B. a bistable MV
C. a latch
D. a monostable MV - SI unit of the permittivity of free space is________________?
A. Nm2C2
B. N-1mC-2
C. NmC-1
D. N-1m-2C2
