Bulbs in street lighting are all connected in_____________?
(A) parallel
(B) series
(C) series-parallel
(D) end-to-end
In the case of direct current____________?
(A) magnitude and direction of current remains constant
(B) magnitude and direction of current changes with time
(C) magnitude of current changes with time
(D) magnitude of current remains constant
Two lamps 100 W and 40 W are connected in series across 230 V (alternating). Which of the following statement is correct ?
(A) 100 W lamp will glow brighter
(B) 40 W lamp will glow brighter
(C) Both lamps will glow equally bright
(D) 40 W lamp will fuse
When current flows through heater coil it glows but supply wiring does not glow because______________?
(A) current through supply line flows at slower speed
(B) supply wiring is covered with insulation layer
(C) resistance of heater coil is more than the supply wires
(D) supply wires are made of superior material
Temperature co-efficient of resistance is expressed in terms of___________?
(A) ohms/°C
(B) mhos/ohm°C
(C) ohms/ohm°C
(D) mhos/°C
A nichrome wire used as a heater coil has the resistance of 2 £2/m. For a heater of 1 kW at 200 V, the length of wire required will be_____________?
(A) 80 m
(B) 60 m
(C) 40 m
(D) 20 m
Two copper conductors have equal length. The cross-sectional area of one conductor is four times that of the other. If the conductor having smaller cross-sectional area has a resistance of 40 ohms the resistance of other conductor will be_____________?
(A) 160 ohms
(B) 80 ohms
(C) 20 ohms
(D) 10 ohms
Which method can be used for absolute measurement of resistances _______________?
(A) Lorentz method
(B) Releigh method
(C) Ohm’s law method
(D) Wheatstone bridge method
Three 6 ohm resistors are connected to form a triangle. What is the resistance between any two corners ___________?
(A) 3/2 Q
(B) 6 Q
(C) 4 Q
(D) 8/3 Q
Three identical resistors are first connected in parallel and then in series. The resultant resistance of the first combination to the second will be_________________?
(A) 9 times
(B) 1/9 times
(C) 1/3 times
(D) 3 times