objective question

1. Electricity
1.Which of the following is the commercial unit of electric power?
[A] Joule
[B] KWh
[C] Watt
[D] Ampere
2.What is the work done to move a unit charge from point to another called as?
[A] Current
[B] Resistance
[C] Conductance
[D] Potential Difference
3.As per Ohm’s law, if the resistance of a conductor is doubled, what will be the
effect on the current flowing through it?
[A] it gets doubled
[B] it gets halved
[C] it increases 4 times
[D] No change
4.Which of the following metals is mostly used for filaments of electric bulbs?
[A] Copper
[B] Silver
[C] Nickel
[D] Tungsten

2. Electricity
5.What is the property of a conductor to resist the flow of charges known as?
[A] Conductance
[B] Conductivity
[C] Resistance
[D] Electric Potential
6.What of the following represents Ohm’s law (V= potential difference and
I=current)?
[A] V = I 2
[B] V = 1/I
[C] V/I = constant
[D] None of the above
7.Which of the following is true about metals?
[A] They are good conductors of electricity
[B] They have low resistivity
[C] Both a and b
[D] None of the above
8.Which of the following is an example of insulator?
[A] Diamond
[B] Mercury
[C] Iron
[D] Chromium

3. Electricity
9.Which of the following is true about the force between two point charges as per
the Coulomb’s law?
[A] inversely as the square of the distance between the charges
[B] directly proportional to the product of the magnitude of the two charges
[C] Both a and b
[D] None of the above
10.What is the value of permittivity of free space?
[A] 8.854 × 10–10 C2 N–1 m–2
[B] 8.854 × 10–11 C2 N–1 m–2
[C] 8.854 × 10–12 C2 N–1 m–2
[D] 8.854 × 10–13 C2 N–1 m–2
11.What is the total charge of the electric dipole?
[A] 0
[B] -1
[C] +1
[D] None of the above
12.What do we call the rate at which electric energy is dissipated or consumed in
an electric circuit?
[A] Conductance
[B] Power
[C] Resistance
[D] Potential Difference

4. Electricity
13.What is current density?
[A] Current per unit volume
[B] Current per unit area
[C] Charge per unit area
[D] None of the above
14.What do we call the magnitude of the drift velocity per unit electric field?
[A] Current Density
[B] Mobility
[C] Conductance
[D] Resistance
15.What number does orange colour represent in the resistance colour code?
[A] 1
[B] 2
[C] 3
[D] 4
16.Which of the following represents Electric Power (V=Voltage, I=Current)?
[A] V x I
[B] V/I
[C] 2( V x I)
[D] 1/VI

5. Electricity
17.What is the S.I. unit of electric charge?
[A] Ampere
[B] Coulomb
[C] Joule
[D] Watt
18.Which of the following represents the unit ampere?
[A] Kg/metre
[B] coulomb/metre
[C] coulomb/second
[D] Kg/coulomb
19.How many electrons constitutes a 1 coulomb charge?
[A] 3 × 1016
[B] 6 × 1018
[C] 9 × 1021
[D] 1
20.On which of the following does the resistance of a conductor depend?
[A] Length
[B] Area of cross-section
[C] Nature of material
[D] All of the above