Why are electric field lines perpendicular at a point on an equipotential surface of a conductor ?
For any charge configuration, equipotential surface through a point is normal to the electric field. Justify.
Choose the SI unit of electric potential energy :
(a) Joule
(b) Coulomb
(c) Newton per coulomb
(d) Erg
The electric potential due to point charge 3 nC at distance of 9 cm is
(a) 270 v
(b) 3 v
(c) 300 v
(d) 30 v
In the given figure, charge +Q is placed at the centre of a dotted circle. Work done in taking another charge +q from A to B is W₁ and from B to C is W₂. Which one of the following is correct ?
i) W₁ > W₂
(ii) W₁ = W₂
(iii) W₁ < W₂
State which of the two a capacitor or an inductor, tends to become SHORT when the frequency of the applied alternating voltage has a high value.
A charge ‘q’ is moved from a point A above a dipole of dipole moment ‘p’ to a point B below the dipole in equatorial plane without acceleration. Find the work done in the process.
A 10 V battery of negligible internal resistance is connected across a 200 V battery and a resistance of 38Ω as shown in the figure. Find the value of the current in the circuit.
Two identical cells, each of emf E, having negligible internal resistance, are connected in parallel with each other across an external resistance R. What is the current through this resistance ?
Why is the use of ac voltage preferred over dc voltage ? Give two reasons.