Plot a graph showing the variation of current I versus resistance R, connected to a cell of emf E and internal resistance r.
In the two electric circuits shown in the figure, determine the readings of ideal ammeter (A) and the ideal voltmeter (V).
Draw a graph to show the variation of resistance of a metal wire as a function of its diameter keeping its length and material constant.
Give an example of a material each for which temperature coefficient of resistivity is:
(i) positive, (ii) negative.
The V-i graph for a conductor at temperature T¹ and T² are as shown in the figure. (T² - T¹) is proportional to
(a) cos θ
(b) sin θ
(c) cot 2θ
(d) tan θ
Using the concept of drift velocity of charge carriers in a conductor, deduce the relationship between current density and resistivity of the conductor.
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.
Write the expression for the drift velocity of charge carriers in a conductor of length l across which a potential difference V is applied.
Two equal balls having equal positive charge ‘q’ coulombs are suspended by two insulating strings of equal length. What would be the effect on the force when a plastic sheet is inserted between the two ?
A point charge +Q is placed at point O as shown in the figure. Is the potential difference VA – VB positive, negative or zero ?
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
A point charge +Q is placed in the vicinity of a conducting surface. Draw the electric field lines between the surface and the charge.
The emf of a cell is always greater than its terminal voltage. Why ? Give reason.
