Q3 of 46 Page 271

Find the total current that passes through the circuit given in the diagram. Also find the potential difference across 1Ω resistor.

To find the total current(I) passing through the circuit, we must find the total resistance(R) and also we know the battery’s potential difference(V) which is 1.5 V , so by Ohm’s law we can find the net current flowing in the circuit.

As we can see by the figure that two resistors 1 ohm and 2 ohm are in series to each other, so we can directly add them , 1 + 2 = 3 ohm,


Also we can see that 3 resistors 4 ohm , 6 ohm , and 12 ohm are parallel to each other , so , let the net parallel resistance of these three resistors be Rp ,



Therefore, Rp = 2 ohm


Hence by Ohm’s law, V = I× R



As the current passing through 1 ohm resistor is the net current flowing in the circuit, so


V = I× R = 0.75× 1 = 0.75 V. It is the potential difference(V) across the 1 ohm resistor.


More from this chapter

All 46 →
1

Veena’s car radio will run from a 12 V car battery that produces a current of 0.20 A even when the car engine is turned off. The car battery will no longer operate when it has lost 1.2 x 106 J of energy. If Veena gets out of the car, leaving the radio on by mistake, how long will it take for the car battery to go completely dead, i.e. lose all energy?

(1 day = 86400 second)

 2

Find the total current that passes through the circuit. Find the heat generated across the each resistor.

 4

Raman’s air-conditioner consumes 2160 W of power, when a current of 9.0 A passes through it.

i) What is the voltage drop when the air-conditioner is running?


ii) How does this compare to the usual household voltage?


iii) What would happen if Raman tried connecting his air-conditioner to a 120V line?

 5

The effective resistance of three resistors connected in parallel is 60/47 Ω. When one wire breaks, the effective resistance becomes 15/8 ohms. Find the resistance of the wire that is broken.