a) Go quickly to 100 ohms and remain there b) Show low resistance momentarily and back off to a very high resistance c) Not move at all d) Show very high resistance first and then low Ans: (b)
a) Voltage coil inductance b) Voltage coil capacitance c) Eddy currents d) (a), (b) and (c) Ans: (d)
a) One wattmeter method b) Two wattmeter method c) Three wattmeter method d) Ammeter method Ans: (b)
a) The power when load is balance in three phase circuit b) The power when load is unbalanced in three phase circuit c) (a) or (b) d) Single phase power with balanced load Ans: (a)
a) 90° b) 180° c) 45° d) 0° e) 120° Ans: (a)
a) True b) False Ans: (b)
a) One wattmeter b) One wattmeter and one voltage transformer of 1:1 ratio c) One wattmeter and two current transformers of 1:1 ratio d) Either (b) or (c) Ans: (d)
a) P = 3VI cos ϕ b) P = √I cos ϕ c) P = √3VI cos ϕ d) P = √2VI cos ϕ Ans: (c)
Where V and I are the line voltage and line current respectively.
a) P = 3 VI cos ϕ b) P = √3 VI cos ϕ c) P = √2 VI cos ϕ d) P = √3 VI sin ϕ Ans: (b)
a) AC power only b) DC power only c) AC or DC power d) AC power of single-phase circuits Ans: (c)