Advertisements
Advertisements
प्रश्न
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?
Advertisements
उत्तर
Given: Voltage of power source (V) = 220 V
Resistance of coil A R1 = 24 Ω
Resistance of coil B R2 = 24 Ω
(a) In the first case - when these coils are connected to separate power sources, then
Current flowing I = `"V"/"R"_1 = "V"/"R"_2 = 220/24` = 9.2 A
Therefore, current flowing through each coil is 9.2 A
(b) In the second case - when they are connected in series, then the total resistance
R = R1 + R2
= 24 Ω + 24 Ω
= 48 Ω
Therefore, the flowing electric current I = `"V"/"R"`
= `(220 "V")/(48 Ω)`
= 4.58 A
= 4.6 A
(c) In the third case – when the coils are connected in parallel, then the total resistance is,
`1/"R" = 1/"R"_1 + 1/"R"_2`
= `1/24 + 1/24`
= `2/24`
R = `24/2` = 12 Ω
Hence the flowing electric current I = `"V"/"R"`
= `(220 "V")/(12 Ω)`
= 18.33 A
= 18.3 A
APPEARS IN
संबंधित प्रश्न
Differentiate between resistances in series and parallel.
With a neat labelled diagram and derive the equation for three resistances connected in parallel.
How many 176 Ω resistors (in parallel) are required to carry 5 A on a 220 V line?
Several electric bulbs designed to be used on a 220 V electric supply line are rated 10 W. How many lamps can be connected in parallel with each other across the two wires of 220 V line if the maximum allowable current is 5 A?
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?
The figure given below shows three resistors?
Their combined resistance is:
(a) `1 5/7`Ω
(b) `14` Ω
(c) `6 2/3` Ω
(d) `7 1/2` Ω
A resistor of 8 ohms is connected in parallel with another resistor X. The resultant resistance of the combination is 4.8 ohms. What is the value of the resistor X?
If current flows through two lamps arranged:
(a) in series,
(b) in parallel,
and the filament of one lamps breaks, what happens to the other lamp? Explain your answer.
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 equivalent resistance is less than either of the two resistances.
Which of the following combinations have the same equivalent resistance between X and Y?
Four resistors each of resistance 2Ω are connected in parallel. What is the effective resistance?
What are the advantages of a parallel connection?
State the S.I. unit of electrical resistance and define it.
A piece of wire having a resistance R is cut into five equal parts.
- How will the resistance of each part of the wire change compared with the original resistance?
- If the five parts of the wire are placed in parallel, how will the resistance of the combination change?
- What will be ratio of the effective resistance in series connection to that of the parallel connection?
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?
Study the following circuit:
On the basis of this circuit, answer the following questions:
i. Find the value of total resistance between the points A and B.
ii. Find the resistance between the points B and C.
iii. Calculate the current drawn from the battery, when the key is closed
OR
iii. In the above circuit, the 16Ω resistor or the parallel combination of two resistors of 8 Ω, which one of the two will have more potential difference across its two ends? Justify your answer.
Two resistors having resistance 8 Ω and 12 Ω are connected in parallel. Find their equivalent resistance.
