1. The number of electrons to be put on a spherical
conductor of radius 0.1 m to produce an electric
field of 0.036 N /C just above its surface is
a) \[2.7 \times 10^{5}\]
b) \[2.6 \times 10^{5}\]
c) \[2.5 \times 10^{5}\]
d) \[2.4 \times 10^{5}\]
Explanation:
2. Two plates are 2 cm apart, a potential difference
of 10 volt is applied between them, the electric
field between the plates is
a) 20 N /C
b) 500 N /C
c) 5 N /C
d) 250 N /C
Explanation:
3.The intensity of the electric field required to keep
a water drop of radius 10-5 cm just suspended in
air when charged with one electron is
approximately
a) 260 volt / cm
b) 260 newton / coulomb
c) 130 volt / cm
d) 130 newton / coulomb
Explanation:
4. Conduction electrons are almost uniformly
distributed within a conducting plate. When
placed in an electrostatic field \[\vec{E}\] , the electric
field within the plate
a) Is zero
b) Depends upon E
c) Depends upon \[\vec{E}\]
d) Depends upon the atomic number of the
conducting element
Explanation: Electric field inside a conductor is zero.
5. Three particles, each having a charge of \[10 \mu C\] are
placed at the corners of an equilateral triangle of
side 10 cm . The electrostatic potential energy of
the system is (Given \[\frac{1}{4\pi\epsilon_{0}} =9\times 10^{9}N-m^{2}/c^{2})\]
a) zero
b) Infinite
c) 27 J
d) 100 J
Explanation:
6. The electric field near a conducting surface
having a uniform surface charge density \[\sigma\] is
given by
a) \[\frac{\sigma}{\epsilon_{0}}\] and is parallel to the surface
b) \[\frac{2\sigma}{\epsilon_{0}}\]and is parallel to the surface
c) \[\frac{\sigma}{\epsilon_{0}}\] and is normal to the surface
d) \[\frac{2\sigma}{\epsilon_{0}}\] and is normal to the surface
Explanation:
7. There is an electric field E in X-direction. If the
work done on moving a charge 0.2 C through a
distance of 2 m along a line making an angle \[60^{\circ}\]
with the X-axis is 4.0, what is the value of E
a) \[\sqrt{3}N/C\]
b) 4 N /C
c) 5 N /C
d) None of these
Explanation:
8. Four equal charges Q are placed at the four
corners of a square of each side is 'a' . Work done
in removing a charge – Q from its centre to
infinity is
a) o
b) \[\frac{\sqrt{2}Q^{2}}{4\pi\epsilon_{0}a}\]
c) \[\frac{\sqrt{2}Q^{2}}{\pi\epsilon_{0}a}\]
d) \[\frac{Q^{2}}{2\pi\epsilon_{0}a}\]
Explanation:
9.A particle A has charge \[+q\] and a particle B has
charge \[+4q\] with each of them having the same
mass m . When allowed to fall from rest through
the same electric potential difference, the ratio of
their speed \[\frac{V_{A}}{V_{B}}\]
will become
a) 2 : 1
b) 1 : 2
c) 1 : 4
d) 4 : 1
Explanation:
10. Deutron and \[\alpha -\] particle are put 1 Å apart in air.
Magnitude of intensity of electric field due to
deutron at \[\alpha -\] particle is
a) zero
b) \[2.88\times 10^{11}\] newton / coulomb
c) \[1.44\times 10^{11}\] newton / coulomb
d) \[5.76\times 10^{11}\] newton / coulomb
Explanation:
