Question 1 :
A cylinder of length $l$ and radius $R$ is placed in a uniform electric field $E$ parallel to the cylindrical axis. The total flux through the surface of the cylinder is given by
Question 2 :
12 positive charges of magnitude q are placed on a circleof radius R in a manner that they are equally spaced. Acharge +Q is placed at the centre. If one of the chargesq is removed, then the force on Q is:
Question 3 :
An ebonite rod rubbed with fur and a glass rod rubbed with silk cloth are brought nearer to each other. Then:
Question 4 :
Electric field produced due to an infinitely long straight uniformly charged wire at perpendicular distance of $2 cm$ is $3\times { 10 }^{ 8 }N{ C }^{ -1 }$. Then, linear charge density on the wire is _____________.<br>$\left( K=9\times { 10 }^{ 9 }SI\quad unit \right) $
Question 5 :
Three charges, each of value $Q$, are placed at the vertices of an equilateral triangle. A fourth $q$ is placed at the centre of the triangle. if the charges remains stationary, then $q$ is
Question 6 :
Two uncharged bodies when rubbed against each other get charged. This is known as
Question 7 :
Charge $Q$, is divided into two parts which are then kept some distance apart. The force between them will be maximum if the two parts are having the charge.
Question 8 : <p>A spherical charged conductor has a surface charge density $\sigma $. The electric field on its surface is E and electric potential of the conductor is V. Now the radius of the sphere is halved keeping the charge to be constant. The new values of electric field and potential would be </p>
Question 9 :
Electric field on the axis of a small electric dipole at a distance $r$ is $\overrightarrow{E}_1$ and $\overrightarrow{E}_2$ at a distance $2r$ on a line of perpendicular bisector. Then
Question 12 :
A long string with a charge of $\lambda $ per unit length passes through an imaginary cube of edge length $a$. The maximum flux of the electric field through the cube will be:
Question 13 :
The electric charge developed on glass rod rubbed with silk cloth is different from the charge developed on ebonite rod rubbed with fur.
Question 14 :
Which of the following is true when the distance between two point charges is halved?
Question 15 :
The rod or stem of a gold leaf electroscope is made of
Question 16 :
An $\alpha$ particle is situated in an electric field of strength $15\times {10}^{4}N{C}^{-1}$. Force acting on it is
Question 17 :
The force between two point charges separated by a certain distance is $F$. If each charge is double and the distance between them is also doubled then the force would be
Question 18 :
Consider the electric field due to a non-conducting infinite plane having a uniformcharge density.
Question 19 :
Electric field in a region is given by $E = (2\overrightarrow{i} + 3\overrightarrow{j} - 4\overrightarrow{k})V/m$. Find the potential differences between points $(0, 0, 0)$ and $(1, 2, 3)$ in this region.
Question 20 :
A charge q is placed at the centre of a cubical box of side a with top open. The flux of electric field through the surface of the cubical box is:
Question 21 :
Assertion: Electric filed of a dipole can't be found using only Gauss law. (i.e. without using superposition principle)
Reason: Gauss law is valid only for symmetrical charge distribution.
Question 22 :
Two charges are placed a certain distance apart in air. If a brass plate is introduced between them, the force between them will
Question 23 :
Three rigid rods are joined from an equilateral triangle ABC of side 1 m. Three particles carrying charges 20$\mu$C each are attached to the vertices of the triangle. The whole system is at rest in an inertial frame.The resultant force on the charged particle at A has the magnitude
Question 24 :
Two charged particle of charge $+2q$ & $-q$ are kept at some distance .A particle of charge $+2q$ exerts a force $F$ on a particle of charge $-q$. Find out the force exerted by the particle of charge $-q$ on the particle of charge $+2q$?
Question 25 :
An electric dipole is placed at an angle of $30^o$ with an electric field intensity $2\times 10^5N/C$. It experiences a torque equal to $4Nm.$ The charge on the dipole, if the dipole length is 2 cm, is :<br/>
Question 26 :
An electric dipole kept in a uniform electric field experiences :<br/>
Question 27 :
Assertion(A): Force between two point charges at rest is not changed by the presence of a third point charge between them.<br/>Reason (R): Force between two charges depends on the magnitude of the two charges and separation between them. then,
Question 28 :
Two charged conducting sphere of radii $ r_{1} $ and $ r_{2} $ are at the same potential, then the ratio of the surface charge densitieswill be:
Question 33 :
An oil drop, carrying six electronic charges and having a mass of $1.6 \times 10^{-12} g$, falls with some terminal velocity in a medium. What magnitude of vertical electric field is required to make the drop move upward with the same speed as it was formerly moving downward with? Ignore buoyancy
Question 34 :
When the distance between two charged particles is halved, then the force between them becomes :
Question 35 :
Electric field due to an infinite sheet of charge having surface density $\sigma$ is $E$. Electric field due to an infinite conducting sheet of same surface density of charge is
Question 36 :
The charges $+\ 4q, -q$ and $+4q$ are kept on a straight line at position $(0, 0, 0), (a, 0, 0)$ and $(2a, 0, 0)$ respectively. Considering that they are free to move along the $x-axis$ only
Question 37 :
Find the electric field at a point on the perpendicular bisector of unifromly charged rod, The length of the rod is L. the charge on it is Q and the distance of P from the centre of the rod is a,
Question 38 :
Assertion: If Gaussian surface does not enclose any charge, then $\vec {E}$ at any point on the Gaussian surface must be zero,
Reason: No net charge is enclosed by Gaussian surface, so net flux passing through the surface is zero,
Question 39 :
A neutral rubber rod and a neutral piece of fur have equal amounts of negative and positive charge. When the fur is rubbed against the rod, a transfer of electrons occurs. The transfer of electrons and mass transfer respectively takes place from
Question 40 :
A radio active nucleus (initial mass number A and atomic number Z emits 4$\alpha$- particles and 3 positrons).The ratio of numbers of neutrons to that of protons in the final nucleus will be
Question 41 :
If $Q_1 = 5\mu C$, $Q_2 = 3 \mu C$ and $Q_3= -2 \mu C$, then the net charge in the system is :
Question 42 :
A single electron has change $\displaystyle \left | e \right |= 1.6 \times 10^{-19} C$. If the current passing through a conducting wire is $0.32 A$, how many electrons would pass through the wire In one hour?
Question 43 :
Gravitational force <u>               </u> on the nature of the medium between the charges.
Question 44 :
If a body is charged by rubbing it, its weight :<br/>
Question 45 :
Two nucleons are at a separation of $1\times10^{-15}\ m$. The net force between them is $F_1$ if both are neutrons, $F_2$ if both are protons and $F_3$ if one is a proton and other is a neutron. In such a case
Question 46 :
A charged oil drop is suspended in uniform field of $3\times 10^4V/m$ so that it neither falls nor rises. The charge on the drop will be: (Take the mass of the charge $=9.9\times 10^{-15}$kg and $g=10m/s^2$)
Question 48 :
A charge $\mathit{q}$ of mass $\mathit{m}$ that is free to move is placed at the origin of a coordinate system.<br>A second identical charge, but of twice the mass, is placed at a distance $d$ along the positive $x$ axis from the origin.<br>Which of the following correctly describes the magnitude and direction of the force acting on the particle at the origin?
Question 49 :
There are three concentric thin sphere of radius a, b, c ( a > b > c ) . the total surface charges densities on their surfaces are $ \sigma , - \sigma , \ sigma $ respectively. the magnitude of electric field at r ( distance from centre ) such that a > r > b is :
