Physics M.C.Q (1 Marks)

Two identical point charges are placed at a separation of d. P is a point on the line joining the charges, at a distance x from any one charge. The field at P is E, E is plotted against x for values of x from close to zero to slightly less than d. Which of the following represents the resulting curve

Two condensers of capacities 2C and C are joined in parallel and charged upto potential V. The battery is removed and the condenser of capacity C is filled completely with a medium of dielectric constant K. The p.d. across the capacitors will now be

Equipotential surfaces are shown in figure. Then the electric field strength will be

Change Q on a capacitor varies with voltage V as shown in the figure, where Q is taken along the X-axis and V along the Y-axis. The area of triangle OAB represents

An infinite number of identical capacitors each of capacitance 1 μF are connected as in adjoining figure. Then the equivalent capacitance between A and B is

To form a composite 16Μf, 1000 V capacitor from a supply of identical capacitors marked 8 μF, 250 V we require a minimum number of capacitors

Five identical plates each of area A are joined as shown in the figure. The distance between the plates is d. The plates are connected to a potential difference of V volts. The charge on plates 1 and 4 will be

Capacitance of a capacitor made by a thin metal foil is 2μF. If the foil is folded with paper of thickness 0.15 mm, dielectric constant of paper is 2.5 and width of paper is 400 mm , then length of foil will be

A dielectric slab of thickness d is inserted in a parallel plate capacitor whose negative plate is at x = 0 and positive plate is at x = 3d. The slab is equidistant from the plates. The capacitor is given some charge. As one goes from 0 to 3d

A parallel plate air capacitor has a capacitance of 100 μμF. The plates are at a distance d apart. If a slab of thickness t( t ≤ d) and dielectric constant 5 is introduced between the parallel plates, then the capacitance will be

Four charges equal to – Q are placed at the four corners of a square and a charge q is at its centre. If the system is in equilibrium the value of q is

Six charges, three positive and three negative of equal magnitude are to be placed at the vertices of a regular hexagon such that the electric field at O is double the electric field when only one positive charge of same magnitude is placed at R. Which of the following arrangements of charges is possible for P, Q, R, S, T and U respectively

Two point charges (+Q) and (-2Q) are fixed on the X-axis at positions a and 2a from origin respectively. At what positions on the axis, the resultant electric field is zero

A point charge of 40 stat coulomb is placed 2 cm in front of an earthed metallic plane plate of large size. Then the force of attraction on the point charge is

A solid conducting sphere having a charge Q is surrounded by an uncharged concentric conducting hollow spherical shell. Let the potential difference between the surface of the solid sphere and that of the outer surface of the hollow shell be V. If the shell is now given a charge of –3Q, the new potential difference between the same two surfaces is

An elementary particle of mass m and charge +e is projected with velocity v at a much more massive particle of charge Ze, where Z > 0. What is the closest possible approach of the incident particle 

A finite ladder is constructed by connecting several sections of 2μF,4 μF capacitor combinations as shown in the figure. It is terminated by a capacitor of capacitance C. What value should be chosen for C such that the equivalent capacitance of the ladder between the points A and B becomes independent of the number of sections in between

Two equal point charges are fixed at x = -a and x = +a on the x-axis. Another point charge Q is placed at the origin. The Change in the electrical potential energy of Q, when it is displaced by a small distance x along the x-axis, is approximately proportional to(a) (b) (c) (d)

The electric potential at a point (x, y) in the x - y plane is given by V = -kxy. The field intensity at a distance r from the origin varies as

In the figure a potential of + 1200 V is given to point A and point B is earthed, what is the potential at the point P

A uniform electric field pointing in positive x-direction exists in a region. Let A be the origin, B be the point on the x-axis at x = +1 cm and C be the point on the y-axis at y = +1 cm. Then the potentials at the points A, B and C satisfy 

Consider two points 1 and 2 in a region outside a charged sphere. Two points are not very far away from the sphere. If E and V represent the electric field vector and the electric potential, which of the following is not possible

Charge q is uniformly distributed over a thin half ring of radius R. The electric field at the centre of the ring is

The charge on 500 cc of water due to protons will be

A non-conducting solid sphere of radius R is uniformly charged. The magnitude of the electric field due to the sphere at a distance r from its centre

A charged particle q is shot towards another charged particle Q which is fixed, with a speed v. It approaches Q upto a closest distance r and then returns. If q were given a speed 2v, the closest distances of approach would be

A solid metallic sphere has a charge +3Q. Concentric with this sphere is a conducting spherical shell having charge -Q. The radius of the sphere is a and that of the spherical shell is b(b > a). What is the electric field at a distance R(a < R < b) from the centre 

Two equal charges q of opposite sign separated by a distance 2a constitute an electric dipole of dipole moment p. If P is a point at a distance r from the centre of the dipole and the line joining the centre of the dipole to this point makes an angle θ with the axis of the dipole, then the potential at P is given by (r >> 2a) (Where p = 2qa)

A point charge q is placed at a distance a/2 directly above the centre of a square of side a. The electric flux through the square is

An ellipsoidal cavity is carved within a perfect conductor. A positive charge q is placed at the centre of the cavity. The points A and B are on the cavity surface as shown in the figure. Then

A metallic shell has a point charge ‘q’ kept inside its cavity. Which one of the following diagrams correctly represents the electric lines of forces

Three capacitors of capacitance 1 mF, 2 mF and 3 mF are connected in series and a potential difference of 11 V is applied across the combination. Then, the potential difference across the plates of 1 mF capacitor is

Effective capacitance between A and B in the figure shown is (all capacitance are in mF)

Three capacitors 2, 3 and 6 mF are joined in series with each other. What is the minimum effective capacitance

Three plates of common surface area A are connected as shown. The effective capacitance will be

All six capacitors shown are identical, Each can withstand maximum 200 volts between its terminals. The maximum voltage that can be safely applied between A and B is

In the figure, three capacitors each of capacitance 6 pF are connected in series. The total capacitance of the combination will be