Electrodynamics...

Directions: The following question has four choices out of which ONLY ONE is correct.
Seven conductors each of resistance R are arranged as shown in the figure. (i), fig. (ii) and fig. (iii). If R₁, R₂ and R₃ are the respective equivalent resistances between A and B, then

Directions: The following question has four choices out of which ONLY ONE is correct.

Following question contains statements given in two columns, which have to be matched. The statements in Column I are labeled A, B, C and D, while the statements in Column II are labeled p, q, r, s and t. Any given statement in Column I can match with ONE OR MORE statements (s) in column II. The appropriate bubbles corresponding to the answers to these questions have to be darkened as illustrated in the following example:

If the correct matches are A - p, s and t; B - q and r, C - p and q; and D - s and t: the correct darkening of bubbles will look the following.

Directions: The following question has four choices out of which ONLY ONE is correct.

An unknown resistance R is connected to two cells E₁ and E₂ of negligible internal resistance across AB as shown below:



The emf of cell E₁ is

Directions: The following question has four choices out of which ONLY ONE is correct.

An unknown resistance R is connected to two cells E₁ and E₂ of negligible internal resistance across AB as shown below:



The potential drop across A and B must be

Directions: The following question has four choices out of which ONLY ONE is correct.

An unknown resistance R is connected to two cells E₁ and E₂ of negligible internal resistance across AB as shown below:



The unknown resistance R is found to be

Four capacitors are connected in a circuit, as shown in the figure. The effective capacitance (in µF) between P and Q will be

Two conducting spheres A and B of respective radii a and b are at the same potential. The ratio of the surface charge densities of A and B is

Three charges 2q, -q and -q are located at the vertices of an equilateral triangle. At the circumcentre of the triangle,

A particle of mass m carrying charge q is kept at rest in a uniform electric field E and then released. The kinetic energy gained by the particle, when it moves through a distance y, is

Directions: The following question has four choices out of which ONLY ONE is correct.

C, V, U and Q are capacitance, potential difference, energy stored and charge of a parallel plate capacitor respectively. The quantities that increase when a dielectric slab is introduced between the plates without disconnecting the battery are

Directions: The following question has four choices out of which ONLY ONE is correct.

A heater of 220 V heats a volume of water in 5 minutes. The same heater when connected to 110 V heats the same volume of water in

Directions: The following question has four choices out of which ONLY ONE is correct.

Two different conductors have the same resistance at 0^oC. It is found that the resistance of the first conductor at t₁^oC is equal to the resistance of the second conductor at t₂°C. The ratio of the temperature coefficients of resistance of the conductors, is

Directions: The following question has four choices out of which ONLY ONE is correct.

In the given circuit diagram the current through the battery and the charge on the capacitor respectively in steady state are

Directions: The following question has four choices out of which ONLY ONE is correct.

A potentiometer wire of length 10 m and resistance 20 is connected in series with a 15 V battery and an external resistance of 40. A secondary cell of emf E in the secondary circuit is balanced by 240 cm long potentiometer wire. The emf E of the cell is

Two parallel, large and thin metal plates have equal surface charge densities ( = 26.4 x 10^-12 C/m²) of opposite signs. The electric field between these plates is

Three charged capacitors of capacitance , respectively, having charge each are connected with resistor of resistance through switch S. S is closed at time t = 0. For this given situation, the initial current in the circuit is

In the given figure, . Block A is neutral while charge on B is . Block B is released from rest at a distance of 1.8 m from A on the smooth horizontal surface. Initially, the spring has its free length and assume the blocks to be point masses.



The amplitude of oscillation of the combined mass will be

In the given circuit, it is observed that current I is independent of the value of the resistance R₆. The resistance value must satisfy

Directions: The following question has four choices out of which ONE or MORE is/are correct.

A parallel plate capacitor is charged and the charging battery is then disconnected. If the plates of the capacitor are moved farther apart by means of insulating handles

An elliptical 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 the