Q.1 In plate earthing, the size of copper plate _____ is used.
A. 300 mm x 300 mm x 3 mm
B. 100 mm x100 mm x 1 mm
C. 600 mm x 600 mm x 3 mm
D. 200 mm x 200 mm x 2 mm
Ans.: C
Q. 2 In plate earthing, the size of Aluminium plate _____ is used.
A. 600 mm x 600 mm x 6 mm
B. 200 mm x 200 mm x 2 mm
C. 600 mm x 600 mm x 3 mm
D. 600 mm x 600 mm x 30 mm
Ans.: A
Q. 3 In plate earthing, the plate is buried vertically in the ground at the depth of ___.
A. not less than 1.5m
B. not less than 3m
C. not less than 1m
D. not less than 0.5m
Ans.: B
Q.4 Alternate layer of _____ and ____ each 150 cm thick are kept around plate of the plate earthing method.
A. charcoal, soil
B. charcoal, concrete
C. charcoal, salt
D. any of the above
Ans.: C
Q.5 In plate earthing, four to five bucket of water is poured at the regular of few days. This is because of__.
A. to increase earth resistance
B. to reduced earth resistance
C. to increase earth potential
D. to decrease earth potential
Ans.: B
Q. 6 The plate earthing system is employed for the _____ and the _____ where there is possibility of more fault.
A. generator, substation
B. substation, transmission line
C. transmission line, big power stations
D. transmission line, small power station
Ans.: D
Q.7 In pipe earthing, ______ pipe is used.
A. galvanized iron
B. aluminium
C. iron
D. any of the above
Ans.: A
Q.8 The size of the galvanized iron pipe used in pipe earthing methods.
A. 25 mm diameter and 1 to 1.5 m long
B. 38 mm diameter and 2 to 2.5 m long
C. 10 mm diameter and 1 to 2 m long
D. 50 mm diameter and 2 to 2.5 m long
Ans.: B
Q.9 A pit of size ______ made of concrete and 12.5 cm thick is constructed above the end of pipe in pipe earthing method.
A. 30 mm x 30 mm x 30 mm
B. 40 mm x 40 mm x 40 mm
C. 50 mm x 50 mm x 50 mm
D. any of the above
Ans.: A
A. large power station, small sub station
B. small power stations, sub stations
C. transmission line, large power station
D. Generating station, large power station
Ans.: B
Q.11 Small holes of _____ diameter are drilled at the spacing of __ in pipe earthing.
A. 10mm, 10 cm
B. 12 mm, 12 mm
C. 12 mm, 15cm
D. 12cm, 15mm
Ans.: C
Q.12 Plate and pipe earthing are used where the soil is ____.
A. comparatively soft
B. soil may be sandy
C. rocky
D. any of the above
Ans.: A
Q.13 In coil earthing method, alternate layer of charcoal and salt each ___ thick are provided around the coil.
A. 150mm
B. 300mm
C. 450mm
D. 600mm
Ans.: B
Q.14 Coil earthing is employed for the earthing of the ___.
A. distribution substation
B. Intermediate substation
C. Transmission line
D. distribution poles
Ans.: D
Q.15 Special earthing methods are employed for land is like sandy, rock ect.
A. method of earthing in sandy bed
B. method of earthing in rocky bed
C. method of earthing of extra high voltage system
D. all of the above
Ans.: D