1.A uniform electric field having a magnitude \[E_{0}\] and direction along the positive x- axis exists. If
the potential V is zero at \[x=0\] , then its value at
\[X=+x\] will be
a) \[v_{\left(x\right)}=+xE_{0}\]
b) \[v_{x}=-xE_{0}\]
c) \[v_{x}=+x^{2}E_{0}\]
d) \[v_{x}=-x^{2}E_{0}\]
Explanation:
2.Three charges \[2q,-q,-q\] are located at the
vertices of an equilateral triangle. At the centre of
the triangle
a) The field is zero but potential is non-zero
b) The field is non-zero but potential is zero
c) Both field and potential are zero
d) Both field and potential are non-zero
Explanation:
3.Figure shows the electric lines of force emerging
from a charged body. If the electric field at A and
B are \[E_{A}\] and \[E_{B}\] respectively and if the
displacement between A and B is r then
a) \[E_{A}>E_{B}\]
b) \[E_{A}< E_{B}\]
c) \[E_{A}=\frac{E_{B}}{r}\]
d) \[E_{A}=\frac{E_{B}}{r^{2}}\]
Explanation: In non-uniform electric field. Intensity is more, where the lines are more denser.
4. ABC is an equilateral triangle. Charges +q are
placed at each corner. The electric intensity at O
will be
a) \[\frac{1}{4\pi\epsilon_{0}}\frac{q}{r^{2}}\]
b) \[\frac{1}{4\pi\epsilon_{0}}\frac{q}{r}\]
c) zero
d) \[\frac{1}{4\pi\epsilon_{0}}\frac{3q}{r^{2}}\]
Explanation:
5. In the electric field of a point charge q , a certain
charge is carried from point A to B , C , D and
E . Then the work done
a) Is least along the path
AB
b) Is least along the path
AD
c) Is zero along all the
paths AB, AC, AD and
AE
d) Is least along AE
Explanation: ABCDE is an equipotential surface, on equipotential surface no work is done in shifting a charge from one place to another.
6. The magnitude of electric field intensity E is such
that, an electron placed in it would experience an
electrical force equal to its weight is given by
a) mge
b) \[\frac{mg}{e}\]
c) \[\frac{e}{mg}\]
d) \[\frac{e^{2}}{m^{2}}g\]
Explanation:
7. A conductor with a positive charge
a) Is always at +ve potential
b) Is always at zero potential
c) Is always at negative potential
d) May be at +ve , zero or -ve potential
Explanation: May be at positive, zero or negative potential, it is according to the way one defines the zero potential
8. An electron and a proton are in a uniform electric
field, the ratio of their accelerations will be
a) zero
b) Unity
c) The ratio of the masses of proton and electron
d) The ratio of the masses of electron and proton
Explanation:
9.Two parallel plates have equal and opposite
charge. When the space between them is
evacuated, the electric field between the plates is \[2\times 10^{5}V/m\] . When the space is filled with
dielectric, the electric field becomes \[1\times 10^{5}V/m\] .
The dielectric constant of the dielectric material
a) 1/2
b) 1
c) 2
d) 3
Explanation:
10. The insulation property of air breaks down at \[E=3\times 10^{6}\] volt/metre. The maximum charge that
can be given to a sphere of diameter 5m is
approximately (in coulombs)
a) \[2\times 10^{-2}\]
b) \[2\times 10^{-3}\]
c) \[2\times 10^{-4}\]
d) \[2\times 10^{-5}\]
Explanation:
