Q.4 solve this

Q.4 solve this resistance at steam point is 5.400. When the wire is immersed in a hot bath. the resistance becomes 5.8m. Calculate the temperature Of the oil bath and temperature coefficient of resistance Of platinum. [Ans. : a = 0.004'C,• T 2000CJ Three identical cells, each of emf 2V and internal resistance 0.2 Ohm, are connected in series to an external resistor of 7.4 ohm. Calculate the current in the Circuit and the terminal potential difference across an equivalent cell. : I 0.75; V 5.55 VI 4. Calculate the equivalent resistance and current shown by the ammeter in the circuit diagram given. 40 [Ans. : 12 v 5. A storage battery of emf 12V and internal resistance of 1.50 is being charged by a 12V dc supply. How much resistance is to be put in series for charging the battery safely. by maintaining a constant charging current [Ans. : R — 16.50) 6. Three cell are connæted in parallel with their like poles connected together, with wires of negligible resistance. If the emf Of the cell are 2V. IV and 4 V and if their internal resistance are 40, 30 and 2 ohm respectively. find the current through each cell. Ans. : 13 7. 8. A 16 ohm resistance wire is bent to form a square. A source of ernf 9 volt is connected across one Of its Sides. Calculate the potential difference : IVJ across any one of its diagonals. A length Of uniform •heating wire' made Of nichrome has a resistance 720. At what rate is the energy dissipated it a potential difference Of 120V is applied across (a) full length Of wire (b) halt the length ot wire (wire is cut into two). Why is it is not advisable to use the half length of wire? page 4 of 6