IMPORTANT QUESTIONS OF CURRENT ELECTRICITY

CURRENT ELECTRICITY

IMPORTANT QUESTION OF CURRENT ELECTRICITY

THIS ASSIGNMENT PROVIDE  ALL IMPORTANT QUESTIONS OF CURRENT ELECTRICITY CHAPTER .

This question paper is designed for quick revision for the students of class 12th appearing in the class test or board examination , if students have to practice the question of current electricity in broad level click on  complete assignment of electric current

1 (i)State the working principle of a potentiometer. With the help of the circuit diagram, explain how a potentiometer is used to compare the emf’s of two primary cells. Obtain the required expression used for comparing the emf’s.

(ii) write two possible causes for one sided deflection in a potentiometer experiment.

(iii)Which material is used for potentiometer wire and why?

(iv)how can the sensitivity of a potentiometer be increased?

(i) Why are the connections between the resistor in a meter bridge made of thick copper strips?

(ii)Why is it generally preferred to obtain the balance point in the middle of the meter bridge wire?

(iii)which material is used for the meter bridge wire and why?

3. (i)State with the help of a circuit diagram, the working principle of a meter bridge. Obtain the expression used for determining the unknown resistance.

(ii) what happens if the galvanometer and cell are interchanged at the balance point of the bridge?

(iii) why is it considered important to obtain the balance point near the mid- point of the wire?

4. (a) A cell of emf E and internal resistance r is connected across a variable resistor R. Plot a graph showing the variation of terminal potential V with resistance R.

(b) Plot a graph showing the variation of terminal potential difference across a cell of emf E and internal resistance r with current drawn from it. Using this graph how does one determine the emf of the cell?

5. Two conducting wires X and Y of same diameter but different materials are joined in series across a battery. If the number of density of electrons in X is twice than that in Y, then find the ratio of drift velocity of electrons in the two wires.