Advertisements
Advertisements
Question
The circuit diagram given below shows the combination of three resistors R1, R2 and R3:
Find :
(i) total resistance of the circuit.
(ii) total current flowing in the circuit.
(iii) the potential difference across R1.
Advertisements
Solution
(i) As shown in the figure, the resistors R2 and R3 are connected in parallel. Their total resistance is given by:
1/R = 1/R2+ 1/R3
Here, R2 = 3 Ω
R3 = 6 Ω
So,
1/R = 1/3 + 1/6
Or 1/R = (2+1)/6
1/R = 3/6
R = 2 Ω
This resistance is in series with the resistor, R1.
Total resistance = 2 Ω + R1
R1 = 4 Ω
Therefore, total resistance = 2 Ω + 4 Ω = 6 Ω
(ii) The current through the circuit can be calculated as follows:
Current, I = V / R
I = (12 / 6) A
I = 2 A
(iii) The potential difference across R1 = 2 A x 4 Ω = 8 V
APPEARS IN
RELATED QUESTIONS
What does an electric circuit mean?
Draw the electrical symbols of the following components and state its use:
Rheostat (variable resistance)
What is the Flow of Charge Called?
In which direction do electrons flow?
A Radio Set Draws a Current of 0.36 a for 15 Minutes. Calculate the Amount of Electric Charge that Flows Through the Circuit.
A battery of 9 V is connected in series with resistors of 0.2 Ω, 0.3 Ω, 0.4 Ω, 0.5 Ω and 0.12 Ω. How much current would flow through the 12 Ω resistor?
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
In the circuit diagram given below five resistances of 10 Ω, 40 Ω, 30 Ω, 20 Ω, and 60 Ω are connected as shown to a 12 V battery.
Calculate:
(a) total resistance in the circuit.
(b) total current flowing in the circuit.
A battery and three lamps are connected as shown:
Which of the following statements about the currents at X, Y and Z is correct?
(a) The current at Z is greater than that at Y.
(b) The current at Y is greater than that at Z.
(c) The current at X equals the current at Y.
(d) The current at X equals the current at Z.
Which is the better way to connect lights and other electrical appliances in domestic wiring: series circuits or parallel circuits? why?
How does the heat H produced by a current passing through a fixed resistance wire depend on magnitude of current I?
A wire of length 5 m has a resistance of 2.0 Ω calculate:
(a) the resistance of wire of length 1 m
(b) the equivalent resistance if two such wires each of length 2 m are joined in parallel.
(c) the resistance of 1 m length of wire of same material but of half diameter.
Tell the odd one out. Give a proper explanation.
Fig. shows a 3 pin plug with the cover removed. The electric cable
connected to the plug contains 3 wires with colour coded insulation namely brown, blue and green.
- Identify each of the colour coded wires by stating to which of the
terminals A, B or C in the diagram they should be connected. - Identify the terminal through which no current passes in normal
circumstances. - What is the purpose of the earthed wire connected to an electric
appliance like an electric heater? Describe how it works.
One unit of electrical energy consumed is equal to 1000 kilowatt-hour.
When an electric current is passed, electrons move from:
What is the rate at which charges flow past a point on a circuit?
