Author: electricalworld

Q.1 _____ and ____ mechanism should be earthed through separate branch.     A. Circuit breaker, earth switch     B. Isolators, circuit breaker     C. Isolators, earth switch     D. Relay, earth switch Ans.: C Q.2 The poles of the transmission Read More …

Q.1 Plate earthing and pipe earthing are used where the soil is___.     A. Comparatively rocky     B. Comparatively soft     C. comparatively sandy     D. all of the above Ans.: B Q.2 The value of the earth resistance decreases Read More …

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 Read More …

Q.1 What is earth current?     A. The current dissipated by the earth electrode into the ground     B. the current at time of earth fault     C. the current at which the protective system operated     D. all of Read More …

Q.1 The minimum current a human can feel is approximately equal to __.     A. 5 mA     B. 1 mA     C. 10 mA     D. 15 mA Ans.: B Q.2 The perception of electric shock can be depends Read More …

Q.1 What are the objectives of earthing?     A. It provides a path for discharging and de-energizing equipment to carry out maintenance on the equipment     B. protection of human and animals life by controlling touch and step voltage to Read More …