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# Current Electricity ## 2012 **36.** 12 coulombs/minute can be written as (i) 2A (ii) 0.2A (iii) 0.02A (iv) 0.002A **37.** The drift speed of an electron in a uniform conductor is directly proportional to its area of cross section. **38.** Calculate the main current in the given circuit. (C...

# Current Electricity ## 2012 **36.** 12 coulombs/minute can be written as (i) 2A (ii) 0.2A (iii) 0.02A (iv) 0.002A **37.** The drift speed of an electron in a uniform conductor is directly proportional to its area of cross section. **38.** Calculate the main current in the given circuit. (Correct the sentence, if required, without changing the underlined words) * **Diagram:** A circuit showing 3 resistors, each with resistance 3Ω, connected in series. The circuit is powered by a 1.5V battery. * **Answer** 1.5V/(3 + 3 + 3)Ω = 0.5A ## 2013 **39.** A uniform straight conductor of radius 0.25mm carries a steady current of 2A. Calculate the current density in it. **40.** Use kirchhaff's rules to obtain the formula for finding effective resistance in case of parallel combination of resistors. **41.** A wire of non-uniform cross section is carrying a steady current. Along the wire (i) current and current density are constant (ii) only current is constant (iii) only current density is constant (iv)neither current nor current density is constant. **42.** Reciprocal of resistance is called _________. (Conductance) **43.** Four resistances each of one ohm, are connected to form a square. Find the resistance across any one side of the square. ## 2014 **44.** Explain the relation between emf and potential difference with a circuit diagram. **45.** The cross-sectional areas of the conductor Rat a and b in the given circuit are in the ratio 1: 2. If the circuit current is 0.5A, the ratio of the number of electrons flowing through sections at a and b per sec will be * **Diagram:** A circuit diagram representing a battery (k) with a single resistor (R), with a large cross-section at point 'b' compared to point 'a'. * **Answer:** 1:2