AIPMT-PRELIMS Physics Electrostatic Potential and Capacitance Class 12 Questions

Four electric charges +q, +q, -q and -q are placed at the corners of a square of side 2L (see figure). The electric potential at point A, midway between the two charges +q and +q, is

A parallel plate condenser has an electric field E (V/m) in the space between the plates. If the distance between the plates is d (m) and area of each plate is A (m²) the energy (joules) stored in the condenser is

A series combination of n₁ capacitors, each of value C₁, is charged by a source of potential difference 4 V. When another parallel combination of n₂ capacitors, each of value C₂, is charged by a source of potential difference V, it has the same (total) energy stored in it, as the first combination has. The value of C₂ in terms of C₁, is then

Three concentric spherical shells have radii a, b and c (a < b < c) and have surface charge densities σ, -σ and σ respectively. If V_A, V_B and V_C denote the potentials of the three shells, then for c = a + b, we have:

Three capacitors each of capacitance C and of breakdown voltage V are joined in series. The capacitance and breakdown voltage of the combination will be:

The electric potential at a point (x, y, z) is given by V = −x²y − xz³ + 4. The electric field E at that point is:

A thin conducting ring of radius R is given a charge + Q. The electric field at the centre O of the ring due to the charge on the part AKB of the ring is E. The electric field at the centre due to the charge on the part ACDB of the ring is -

The energy required to charge a parallel plate condenser of plate separation d and plate area of cross-section A such that the uniform electric field between the plates is E, is :

A hollow cylinder has a charge q coulomb within it. If ϕ is the electric flux in units of voltmeter associated with the curved surface B, the flux linked with the plane surface A in units of voltmeter will be

Charges +q and –q are placed at points A and B respectively which are a distance 2L apart, C is the midpoint between A and B. The work done in moving a charge +Q along the semicircle CRD is

Two condensers, one of capacity C and other of capacity C/2 are connected to a V⁻volt battery, as shown. The work done in charging fully both the condensers is

A parallel plate air capacitor is charged to a potential difference of V volts. After disconnecting the charging battery the distance between the plates of the capacitor is increased using an insulating handle. As a result the potential difference between the plates:

A network of four capacitors of capacity equal to C₁ = C, C₂ = 2C, C₃ = 3C and C₄ = 4C are connected to a battery as shown in the figure. The ratio of the charges on C₂ and C₄ is:

As per this diagram a point charge -q is placed at the origin O. Work done in taking another point charge -Q from the point A [co-ordinates (0, a)] to another point B [co-ordinates (a, 0)] along the straight path AB is :

Two charges q₁ and q₂ are placed 30 cm apart, as shown in the figure. A third charge q₃ is moved along the arc of a circle of radius 40 cm from C to D. The change in the potential energy of the system is (q₃/4πε₀)k, where k is:

A bullet of mass 2 g is having a charge of 2 μC. Through what potential difference must it be accelerated, starting from rest, to acquire a speed of 10 m/s ?

Three capacitors each of capacity 4 μF are to be connected in such a way that the effective capacitance of 6μF. This can be done by -

Some charge is being given to a conductor. Then its potential :-

A capacitor of capacity C₁ charged upto V volt and then connected to an uncharged capacitor C₂. Then final P.D. across each will be :-

Energy per unit volume for a capacitor having area A and separation d kept at potential difference V is given by : -

A dipole of moment →p is placed in uniform electric field →E then torque acting on it is given by :-

A capacitor is charged with a battery and energy stored is U. After disconnecting battery another capacitor of same capacity is connected in parallel with it. Then energy stored in each capacitor is: