Advertisements
Advertisements
Question
Find the effective resistance in the following circuit diagrams (Fig.):

Advertisements
Solution

In the path ACB, the series combination of two 2Ω resistor is connected in parallel with the third 2Ω resistor.
:. resislancein series= 2 + 2 = 4 Ω
This 4 Ω resistor is now connected in parallel with the 2Ω resistor
total resistance between A and B `(1/"R"_"P") = 1/4 + 1/2 = 3/4 Ω`
`"R"_"P" = 4/3 Omega`
Now, between P and Q, two 2Ω resistors and `4/3` Ω are connected in series.
total resistance of the given network, R, = `2 + 2 + 4/3 = (6 + 6 + 4)/3 = 16/3 = 5.3Ω`
APPEARS IN
RELATED QUESTIONS
Which of the following equation shows the correct relationship between electrical unit?
1A = 1C/s or 1c= 1A/s
Three resistors are connected as shown in the diagram.
Through the resistor 5 ohm, a current of 1 ampere is flowing.
(i) What is the current through the other two resistors?
(ii) What is the p.d. across AB and across AC?
(iii) What is the total resistance
A cell supplies a current of 1.2 A through two 2 Ω resistors connected in parallel. When the resistors are connected in series, it supplies a current of 0.4 A. Calculate:
(i) the internal resistance and (ii) e.m.f. of the cell.
The following table shows the current in Amperes and potential differences in Volts.
- Find the average resistance.
- What will be the nature of the graph between the current and potential difference? (Do not draw a graph.)
- Which law will the graph prove? Explain the law.
| V (volts) | I (amp) |
| 4 | 9 |
| 5 | 11.25 |
| 6 | 13.5 |
Two resistors P and Q of the same material and length but of different thickness are connected in parallel to a battery. The cross- sectional area of P is twice that of Q. What is the ratio of
(a) The resistance of P to the resistance of Q?
(b) The current in P to the current in Q?
Find the effective resistance in the following circuit diagrams (Fig.):

An electric bulb is rated '100 W, 250 V'. How much current will the bulb draw if connected to a 250 V supply?
A bulb is connected to a battery of p.d. 4 V and internal resistance 2.5 Ω . A steady current of 0.5 A flows through the circuit. Calculate:
The energy dissipated in the bulb in 10 minutes.
The SI unit for electric current is the coulomb.
