Electrical Engineering- Electric Current and Ohm's Law
Electrical Engineering- Electric Current and Ohm's Law
Three equal resistors connected in series across a source of emf together dissipate 10 watts of power. What would be the power dissipated in the same resistors when they are connected in parallel across the same source of emf?
- 10 watts
- 30 watts
- 90 watts
- 270 watts.
.Four identical resistors are first connected in parallel and then in series. The resultant resistance of the first combination to the second will be
- 1 / 16 times
- 1 / 4 times
- 4 times
- 16 times.
When P = Power, V = Voltage, I = Current, R = Resistance and G = Conductance, which of the following relation is incorrect?
- V = √ (PR)
- P= V2G
- G= P / I2
- I =√ (P / R)
The unit of electrical conductivity is
- mho / metre
- mho / sq. m
- ohm / metre
- ohm / sq. m.
Which of the following bulbs will have the least resistance ?
- 220 V, 60 W
- 220 V, 100 W
- 115 V, 60 W
- 115 V, 100 W.
The ratio of the resistance of a 100 W, 220 V lamp to that of a 100 W, 110 V lamp will be nearly
- 4
- 2
- 1 / 2
- 1 / 4
Two 1 kilo ohm, 1/2 W resistors are connected in series. Their combined resistance value and wattage will be
- 2 kΩ, 1/2 W
- 2 kΩ, 1 W
- 2 kΩ, 2 W
- l kΩ, 1/2 W.
Which method can be used for absolute measurement of resistances ?
- Ohm's law method
- Wheatstone bridge method
- Releigh method
- Lortentz method.
Three 3 ohm resistors are connected to form a triangle. What is the resistance between any two of the corners?
- 3 / 4 ohms
- 3 ohms
- 2 ohms
- 4/3 ohm.