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Electricity Part II -Questions
1. Explain the two methods of connecting resistors in circuits with the help of circuit diagrams. 2. Write the formulae to calculate the effective resistances when resistors are connected (a) in series and (b) in parallel. 3. How is the total potential difference calculated across a combination of resistors in series? 4. Example 12.7 An electric lamp, whose resistance is 20 Ω, and a conductor of 4 Ω resistance are connected to a 6 V battery (Fig. 12.9). Calculate (a) the total resistance of the circuit, (b) the current through the circuit, and (c) the potential difference across the electric lamp and conductor.
5. Example 12.8 In the circuit diagram given in Fig. 12.10, suppose the resistors R1, R2 and R3 have the values 5Ω , 10 Ω , 30Ω , respectively, which have been connected to a battery of 12 V. Calculate (a) the current through each resistor, (b) the total current in the circuit, and (c) the total circuit resistance.
6. Example 12.9 If in Fig. 12.12, R1 = 10Ω , R2 = 40Ω , R3 = 30Ω , R4 = 20 Ω, R5 = 60Ω , and a 12 V battery is connected to the arrangement. Calculate (a) the total resistance in the circuit, and (b) the total current flowing in the circuit. 7. Why are electrical gadgets connected in parallel not in series? T. Q U E S T I O N S 8. 1. Draw a schematic diagram of a circuit consisting of a battery of three cells of 2 V each, a 5 Ω resistor, an 8 Ω resistor, and a 12 Ω resistor, and a plug key, all connected in series. 9. 2. Redraw the circuit of Question 1, putting in an ammeter to measure the current through the resistors and a voltmeter to measure the potential difference across the 12 Ω resistor. What would be the readings in the ammeter and the voltmeter? 10. 1. Judge the equivalent resistance when the following are connected in parallel – (a) 1 Ω and 106Ω , (b) 1Ω and 103Ω , and 106Ω . 11. 2. An electric lamp of 100Ω,
1. Explain the two methods of connecting resistors in circuits with the help of circuit diagrams. 2. Write the formulae to calculate the effective resistances when resistors are connected (a) in series and (b) in parallel. 3. How is the total potential difference calculated across a combination of resistors in series? 4. Example 12.7 An electric lamp, whose resistance is 20 Ω, and a conductor of 4 Ω resistance are connected to a 6 V battery (Fig. 12.9). Calculate (a) the total resistance of the circuit, (b) the current through the circuit, and (c) the potential difference across the electric lamp and conductor.
5. Example 12.8 In the circuit diagram given in Fig. 12.10, suppose the resistors R1, R2 and R3 have the values 5Ω , 10 Ω , 30Ω , respectively, which have been connected to a battery of 12 V. Calculate (a) the current through each resistor, (b) the total current in the circuit, and (c) the total circuit resistance.
6. Example 12.9 If in Fig. 12.12, R1 = 10Ω , R2 = 40Ω , R3 = 30Ω , R4 = 20 Ω, R5 = 60Ω , and a 12 V battery is connected to the arrangement. Calculate (a) the total resistance in the circuit, and (b) the total current flowing in the circuit. 7. Why are electrical gadgets connected in parallel not in series? T. Q U E S T I O N S 8. 1. Draw a schematic diagram of a circuit consisting of a battery of three cells of 2 V each, a 5 Ω resistor, an 8 Ω resistor, and a 12 Ω resistor, and a plug key, all connected in series. 9. 2. Redraw the circuit of Question 1, putting in an ammeter to measure the current through the resistors and a voltmeter to measure the potential difference across the 12 Ω resistor. What would be the readings in the ammeter and the voltmeter? 10. 1. Judge the equivalent resistance when the following are connected in parallel – (a) 1 Ω and 106Ω , (b) 1Ω and 103Ω , and 106Ω . 11. 2. An electric lamp of 100Ω,