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प्रश्न
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?
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उत्तर
(a) All spaces are connected in parallel.
(b) Let Resistance of Space 5 and 4 be R ohms respectively
Resistance of Space 1 = 2 R ohms
Resistance of Space 2 = 30 ohms
Resistance of Space 3 = 20 ohms
Current = 22 A
V = 220 V
Total Resistance = `"V"/"I"`
`1/("R"_1) + 1/("R"_2) + 1/("R"_3) + 1/("R"_4) + 1/("R"_5) = 1/("R"_("eq"))`
`1/(2 "R") + 1/30 + 1/20 + 1/"R" + 1/"R" = 1/("R"_("eq"))`
`(30 + 2"R" + 3"R" + 60 + 60)/(60 "R") = 1/("R"_("eq"))`
`(150 + 5"R")/(60"R") = 1/("R"_("eq"))`
`"R"_("eq") = (60"R")/(150 + 5"R") = cancel(220)^10/cancel(22)_1`
60 R = 10 (150 + 5R)
60 R = 1500 + 50 R
10 R = 1500
R = 150 Ω
(c) `"I"_3 = "V"/"R"_3`
= `220/20`
= 11A
(d) Electrical Fuses/Mcbs should be placed between the main connection and the rest of the house's electrical appliances to save them from sudden surges in electric current.
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