Electrical Engineering- Electric Current and Ohm's Law
Electrical Engineering- Electric Current and Ohm's Law
1. Resistivity of a wire depends on
- length
- material
- cross section area
- none of the above.
When n resistances each of value r are connected in parallel, then resultant resistance is x. When these n resistances are connected in series, total resistance is
- nx
- rnx
- x / n
- n2 x.
Resistance of a wire is r ohms. The wire is stretched to double its length, then its resistance in ohms is
- r / 2
- 4 r
- 2 r
- r / 4.
Kirchhoff's second law is based on law of conservation of
- charge
- energy
- momentum
- mass.
The diameter of the nucleus of an atom is of the order of
- 10 -31 m
- 10 -25 m
- 10 -21 m
- 10 -14m
The mass of proton is roughly how many times the mass of an electron?
- 184,000
- 184,00
- 1840
- 184.
The charge on an electron is known to be 1.6 x 10-19 coulomb. In a circuit the current flowing is 1 A. How many electrons will be flowing through the circuit in a second?
- 1.6 x 1019
- 1.6 x 10-19
- 0.625 x 1019
- 0.625 x 1012.
Two bulbs marked 200 watt-250 volts and 100 watt-250 volts are joined in series to 250 volts supply. Power consumed in circuit is
- 33 watt
- 67 watt
- 100 watt
- 300 watt.
Which of the following is not the same as watt?
- joule/sec
- amperes/volt
- amperes x volts
- ( amperes )2 x ohm.