2021 CAIE AS & A level October November Physics Paper 22 Q. No. 6 (9702/22/O/N/21) by Sajit C Shakya

2021 CAIE AS & A level October November Physics Paper 22 Q. No. 6 (9702/22/O/N/21) by Sajit Chandra Shakya from Nepal Chapter - CURRENT ELECTRICITY A cell of electromotive force (e.m.f.) 0.48 V is connected to a metal wire X, as shown in Fig. 6.1. The cell has internal resistance. The current in the cell is 0.80 A. Wire X has length 3.0 m, cross-sectional area 1.3 × 10–7m2 and resistance 0.40Ω. (a) Calculate the charge passing through the cell in a time of 7.5 minutes. Calculate the percentage efficiency with which the cell supplies power to wire X. There are 3.2 × 1022 free (conduction) electrons contained in the volume of wire X. For wire X, calculate: (i) the number density n of the free electrons (II) the average drift speed of the free electrons.