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प्रश्न
State the S.I. unit of electrical resistance and define it.
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उत्तर
The S.I. unit of electrical resistance is ohm (Ω). The resistance of a conductor is said to be 1 ohm if 1 ampere current flows through it when the potential difference across its end is 1 volt.
संबंधित प्रश्न
How can three resistors of resistances 2 Ω, 3 Ω and 6 Ω be connected to give a total resistance of 4 Ω ?
Which of the following arrangement, A or B, has the lower combined resistance?
A resistor has a resistance of 176 ohms. How many of these resistors should be connected in parallel so that their combination draws a current of 5 amperes from a 220 volt supply line?
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.
A battery of e.m.f. 15 V and internal resistance 2 `Omega` is connected to tvvo resistors of 4 ohm and 6 ohm joined.
(i) In series,
(ii) In para 1 lel. Find in each case the electrica I energy spent per minute in 6 ohm resistor.
The circuit diagram Fig shows three resistors 2 Ω, 4 Ω and R Ω connected to a battery of e.m.f. 2 V and internal resistance 3 Ω. If main current of 0.25 A flows through the circuit, find:
- the p.d. across the 4 Ω resistor,
- the p.d. across the internal resistance of the cell,
- the p.d. across the R Ω or 2 Ω resistors
- the value of 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, in parallel.
The least resistance obtained by using 2 Ω, 4 Ω, 1 Ω and 100 Ω is:
The diagram above is a schematic diagram of a household circuit. The house shown in the above diagram has 5 usable spaces where electrical connections are made. For this house, the mains have a voltage of 220 V and the net current coming from the mains is 22A.
- What is the mode of connection to all the spaces in the house from the mains?
- The spaces 5 and 4 have the same resistance and spaces 3 and 2 have respective resistances of 20Ω and 30Ω. Space 1 has a resistance double that of space 5. What is the net resistance for space 5.
- What is the current in space 3?
- What should be placed between the main connection and the rest of the house’s electrical appliances to save them from accidental high electric current?
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.
