Derive an expression for electric field of a dipole at a point on the equatorial plane of the dipole. How does the field vary at large distances?
An electric dipole is held in a uniform electric field.
(i) Show that the net force acting on it is zero.
(ii) The dipole is aligned parallel to the field. Find the work done in rotating it through the angle of 180°.
Cathode rays travelling from west to east enter into region of electric field directed towards south to north in the plane of paper. The deflection of cathode rays is towards:
(A) East
(B) West
(C) North
(D) South
Figure shows a point charge + Q, located at a distance R/2 from the centre of a spherical metal shell. Draw the electric field lines for the given system.
An electric dipole is placed in a uniform electric field.
(i) Show that no translatory force acts on it.
(ii) Derive an expression for the torque acting on it.
(iii) Find work done in rotating the dipole through 180°.
In the figure the net electric flux through the area... when the system is in air. On immersing the system in water,the net electric flux through the area
A hollow copper sphere is positively charged. The electric field at its center will be
A. same as that on the surface
B. more than that on the surface
C. less than that on the surface nut not zero
D. zero
A capacitor ‘C’, a variable resistor ‘R’ and a bulb ‘B’ are connected in series to the ac mains in circuit as shown. The bulb glows with some brightness.How will the glow of the bulb change if
(i) a dielectric slab is introduced between the plates of the capacitor, keeping resistance R to be the same;
(ii) the resistance R is increased keeping the same capacitance ?
Five charges, q each are placed at the corners of a regular pentagon of side a.
(i) What will be the electric field at O if the charge from one of the corners (say A) is removed ?
(ii) What will be the electric field at O if the charge q at A is replaced by - q ?
Two point charges q1 and q2 are located at points (a, 0, 0) and (0, b, 0) respectively. Find the electric field due to both these charges at the point (0, 0, c).
Write two properties of equipotential surfaces. Depict equipotential surfaces due to an isolated point charge. Why do the equipotential surfaces get closer as the distance between the equipotential surfaces and the source charge decreases ?
Find the expression for electric field intensity in an axial position due to electric dipole.
A cell of emf E and internal resistance r is connected to two external resistances R₁ and R₂ and a perfect ammeter. The current in the circuit is measured in four different situations :
(i) without any external resistance in the circuit
(ii) with resistance R1 only
(iii) with R1 and R2 in series combination
(iv) with R1 and R2 in parallel combination.
The currents measured in the four cases are 0.42 A, 1.05 A, 1.4 A and 4.2 A, but not necessarily in that order. Identify the currents corresponding to the four cases mentioned above.
Two metallic wires P₁ and P₂ of the same material and same length but different cross-sectional areas A₁ and A₂ are joined together and then connected to a source of emf. Find the ratio of the drift velocities of free electrons in the wires P₁ and P₂ if the wires are connected
(i) in series, and (ii) in parallel.