A wire of resistance R is cut into three equal parts. If these three parts are then joined in parallel, calculate the total resistance of the combination so formed.
Resistors in series
Usually 1 marks a paper · mostly very short answers and MCQs · asked in 3 of the last papers
Notes are being written
The board questions below are real and complete — they come from the CBSE papers themselves. The written notes for this topic are still being prepared.
Board questions on this topic
4 from the CBSE papers we hold — the exact wording the board used.
Show how you would connect three resistors each of resistance 6 ohm, so that the combination has a resistance of 9 ohm. Also justify your answer.
If four identical resistors, of resistance 8 ohm, are first connected in series so as to give an effective resistance R_s, and then connected in parallel so as to give an effective resistance R_p, then the ratio R_s/R_p is
- (a) 32
- (b) 2
- (c) 0.5
- (d) 16
(a) Three resistors R_1, R_2 and R_3 are connected in parallel and the combination is connected to a battery, an ammeter, a voltmeter and a key. Draw suitable circuit diagram to show the arrangement of these circuit components along with the direction of current flowing. (b) Calculate the equivalent resistance of the following network: [network shown: along line A-C-D-B, R_1 = 5 ohm is between A and C and R_4 = 5 ohm is between D and B; between C and D, R_2 = 10 ohm (upper branch) and R_3 = 10 ohm (lower branch) are in parallel].