Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
1 MYou Can’t Miss This Previous Years Questions with Expected Answer/value Points Syllabus:- Current Electricity 7 Marks Electric current, flow of electric charges in a metallic conductor, drift velocity, mobility and their relation with electric current; Ohm’s law, electrical resistance, V-I characteristics (linear and nonlinear), electrical energy and power, electrical resistivity and conductivity. Carbon resistors, colour code for carbon resistors; series and parallel combinations of resistors; effect of temperature on resistance. Emf and potential difference of a cell, internal resistance of a cell, combination of cells in series and in parallel. Kirchhoff’s laws and simple applications. Wheatstone bridge, metre bridge. Potentiometer - principle and its applications to measure potential difference and for comparing emf of two cells; measurement of internal resistance of a cell .--------------------------------------------------------------------------------------------------------------------------Q1. A resistance R is connected across a cell of emf ε and internal resistance r. A potentiometer now measures the potential difference between the terminals of the cell as V. Write the expression for 'r' in terms of ε, V and R. 1 A1. Q2. Define the terms (i) drift velocity, (ii) relaxation time. A conductor of length L is connected to a dc source of emf ε. If this conductor is replaced by another conductor of same material and same area of cross-section but of length 3L, how will the drift velocity change ? 3 A2. 2 Q3. In the circuit shown, R1 = 4 Ω, R2 = R3 = 15 Ω, R1 = 30 Ω and E = 10 V. Calculate the equivalent resistance of the circuit and the current in each resistor. 3 A3. Q4. In the given circuit, assuming point A to be at zero potential, use Kirchhoff's rules to determine the potential at point B. 2 3 Q5. In the metre bridge experiment, balance point was observed at J with AJ = l. (i) The values of R and X were doubled and then interchanged. What would be the new position of balance point ? (ii) If the galvanometer and battery are interchanged at the balance position, how will the balance point get affected ? 2 A5. Q6. Two heating elements of resistances R1 and R2 when operated at a constant supply of voltage, V, consume powers P 1 and P2 respectively. Deduce the expressions for the power of their combination when they are, in turn, connected in (i) series and (ii) parallel across the same voltage supply. 3 4 A6. Q7. 1 A7. Q8. 5 3 A8. OR 6 7 Q9. 1 A9. Q10. 3 A10. Q11. 3 8 A11. Q12. 2 A12. Q13. 5 9 5 A13. 10