Electric potential and capacitance practice · Mixed difficulty

An electric dipole is placed in an electric field generated by a point charge. Then which of the following statements is true?

An electric dipole is kept in non-uniform electric field. It experiences

Two metal spheres of capacitance ${C_1}$ and ${C_2}$ carry some charges. They are put in contact and then separated. The final charges ${Q_1}$ and ${Q_2}$ on them will satisfy

If a dipole of dipole moment $\vec{\text{p}}$ is placed in a uniform electric field $\overrightarrow{\mathrm{E}},$ then torque acting on it is given by

Assertion (A) : If we see along the axis of a charged ring, the magnitude of electric field is minimum at centre and magnitude of electric potential is maximum.

Reason (R): Electric field is a vector quantity while electric potential is scalar.

A point $Q$ lies on the perpendicular bisector of an electrical dipole of dipole moment $p.$ If the distance of $Q$ from the dipole is $r$ (much larger than the size of the dipole), then electric field at $Q$ is proportional to

Two similar parallel-plate capacitors each of capacity $C_0$ are connected in series. The combination is connected with a voltage source of $V_0$. Now, separation between the plates of one capacitor is increased by a distance $d$ and the separation between the plates of another capacitor is decreased by the distance $d / 2$. The distance between the plates of each capacitor was $d$ before the change in separation. Then, select the correct choice.

A capacitor of capacitance $C$ has charge $Q$ and stored energy is $W.$ If the charge is increased to $3Q,$ the stored energy will be

Dielectric constant of a medium is also known as:

A potential difference of $300\;volts$ is applied to a combination of $2.0\mu F$ and $8.0\mu F$ capacitors connected in series. The charge on the $2.0\mu F$ capacitor is

The energy stored in a capacitor of capacitance $100 \mu F$ is $50 J$. Its potential difference is

An electric dipole of moment $\vec{P}$ placed in a uniform electric field $\vec{E}$ has maximum potential energy when the angle between $\vec{P}$ and $\vec{E}$ is

For measurement of potential difference, potentiometer is preferred in comparison to voltmeter because:-

A parallel plate air capacitor has a capacitance of $100\mu \mu F.$ The plates are at a distance $d$ apart. If a slab of thickness $t\left( {t \le d} \right)$ and dielectric constant 5 is introduced between the parallel plates, then the capacitance will be

A capacitor of capacitance $C_1$ is charged to a potential $V$ and then connected in parallel to an uncharged capacitor of capacitance $C_2$. The final potential difference across each capacitor will be

An electric field $(-30 \hat{\mathrm{i}}+20 \hat{\mathrm{j}}) \mathrm{Vm}^{-1}$ exists in the space. If potential at the origin is zero then potential at $(5 \mathrm{~m}, 3 \mathrm{~m})$ is given by

The mean free path of electrons in a metal is $4 \times {10^{ - 8}}m.$ The electric field which can give on an average $2\;eV$ energy to an electron in the metal will be in units of $V/m$

A closed solid conductor of irregular shape is given some charge. Which of the following statement is correct?

The plates of a charged condenser is connected to a voltmeter. If the plates are moved apart, the reading of voltmeter will

A charge of $Q\;\mathrm{ }coulomb$ is placed on a solid piece of metal irregular shape. The charge will distribute itself

Work done in carrying a charge around an equipotential surface will

In an electric field $\mathbf{E}$, the torque acting on a dipole moment $\mathbf{p}$ is

Potential and potential gradient is a:

Three capacitors each of capacitance $1 \mu \mathrm{F}$ are connected in parallel. To the combination, a fourth capacitor of capacitance $1 \mu \mathrm{F}$ is connected in series. The resultant capacitance of the system is

If the force exerted by an electric dipole on a charge q at a distance of 1 m is F, the force at a point 2 m away in the same direction will be

Assertion (A): Two capacitor of same capacity are connected first in parallel and then in series. The ratio of resultant capacities in the two cased will be $4: 1.$

Reason (R): In parallel, capacity increases and in series capacity decreases.

If the charge on a capacitor is doubled, the value of its capacitance $C$ will be

Assertion:- A parallel plate capacitor is connected across a battery through a key. A dielectric slab of dielectric constant $K$ is introduced between the plates. The energy which is stored becomes $K$ times.
Reason:- The potential difference between the plates remains constant or unchanged.

If there are $n$ capacitors in parallel connected to $V\;volt$ source, then the energy stored is equal to

If a charged spherical conductor of radius $10cm$ has potential $V$ at a point distant $5\;cm$ from its centre, then the potential at a point distant $15\;cm$ from the centre will be