Advertisements
Advertisements
Question
How can three resistors of resistances 2 Ω, 3 Ω and 6 Ω be connected to give a total resistance of 4 Ω ?
Advertisements
Solution
There are three resistors of resistances: 2 Ω, 3 Ω, and 6 Ω, respectively.
The following circuit diagram shows the connection of the three resistors.
Here, 6 Ω and 3 Ω resistors are connected in parallel.
Therefore, their equivalent resistance will be given by
`1/(1/6+1/3)`
= `(6xx3)/(6+3)`
= 2 Ω
This equivalent resistor of resistance 2 Ω is connected to a 2 Ω resistor in series.
Therefore, the equivalent resistance of the circuit = 2 Ω + 2 Ω = 4 Ω
Hence the total resistance of the circuit is 4 Ω.
APPEARS IN
RELATED QUESTIONS
Complete the following :-
(c)
A hot plate of an electric oven connected to a 220 V line has two resistance coils A and B, each of 24 Ω resistances, which may be used separately, in series, or in parallel. What are the currents in the three cases?
Show how you would connect two 4 ohm resistors to produce a combined resistance of (a) 2 ohms (b) 8 ohms.
Explain with diagram what is meant by the "series combination" and "parallel combination" of resistances. In which case the resultant resistance is : (i) less, and (ii) more, than either of the individual resistances?
Explain with the help of a labelled circuit diagram, how you will find the resistance of a combination of three resistors of resistances R1, R2 and R3 joined in parallel.
Show with the help of diagrams, how you would connect three resistors each of resistance 6 Ω, so that the combination has resistance of (i) 9 Ω (ii) 4 Ω.
How will you connect three resistors of 2 Ω, 3 Ω and 5 Ω respectively so as to obtain a resultant of 2.5 Ω? Draw the diagram to show the arrangement.
How will you connect three resistors of resistances 2 Ω, 3 Ω, and 6 Ω to obtain a total resistance of 4 Ω, and 1 Ω?
Two exactly similar electric lamps are arranged (i) in parallel, and (ii) in series. If the parallel and series combination of lamps are connected to 220 V supply line one by one, what will be the ratio of electric power consumed by them?
State how are the two resistors joined with a battery when potential difference is same across each resistor.
A combination consists of three resistors in series. Four similar sets are connected in parallel. If the resistance of each resistor is 2 ohm, find the resistance of the combination.
In the following figure calculate:
- the total resistance of the circuit
- the value of R, and
- the current flowing in R.
A particular resistance wire has a resistance of 3 ohm per meter. Find the total resistance of three lengths of this wire each 1.5 m long, joined in parallel.
What is the equivalent resistance of 5 equal resistors, each of value 2`Omega` 1 when oonnected in (a) Series ( b) ParaIleI?
Show how would you connect three resistors, each of resistance 6 O so that
the combination has a resistance of(a) 9 Ω (b) 4 .Ω
A particular resistance wire has a resistance of 3 ohm per meter. Find the potential difference of the battery which gives a current of 2 A in each of the 1.5 m length when connected in the parallel to the battery (assume that resistance of the battery is negligible).
Assertion: When a battery is short circuited, the terminal voltage is zero.
Reason: In a short circuit, the current is zero.
You are given four ammeters A, B, C and D having the least counts mentioned below:
(I) Ammeter A with least count 0.25 A
(II) Ammeter B with least count 0.5 A
(III) Ammeter C with least count 0.05 A
(IV) Ammeter D with least count 0.1 A
Which of the ammeters would you prefer for doing an experiment to determine the equivalent resistance of two resistances most accurately, when connected in parallel?
Three resistors of 6Ω, 4Ω and 4Ω are connected together so that the total resistance is 8Ω. Draw a diagram to show this arrangement and give reason to justify your answer.
