Advertisements
Advertisements
प्रश्न
A particular resistance wire has a resistance of 3·0 ohm per metre. Find the resistance of 5 m length of a wire of the same material, but with twice the area of cross section.
Advertisements
उत्तर
R = `ρ l/a` ...(i)
∵ the wire's substance is the same, ρ will stay the same
l1 = 5l and l = 1m, a1 = 2a
∴ R1 = ρ `l_1/a_1`
or R1 = ρ `(5l)/(2a)` ...(ii)
(ii) ÷ (i)
`"R"_1/"R" = (ρ(5l)/(2a))/(ρ(l)/(a)`
= `5/2`
R1 = `5/2 "R"`
= `5/2 xx (3.0)`
= 7.5 Ω
APPEARS IN
संबंधित प्रश्न
How many 176 Ω resistors (in parallel) are required to carry 5 A on a 220 V line?
Show how would you join three resistors, each of resistance 9 Ω so that the equivalent resistance of the combination is
1) 13.5
2) 6 Ω
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?
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.
You have three resistors of values 2Ω, 3Ω and 5Ω. How will you join them so that the total resistance is less than 1Ω? Draw diagram and find the total resistance.
Two resistors of resistance 4 Ω and 6 Ω are connected in parallel to a cell to draw 0.5 A current from the cell.
Draw a labeled diagram of the arrangement
Two resistors of resistance 4 Ω and 6 Ω are connected in parallel to a cell to draw 0.5 A current from the cell.
Calculate current in each resistor.
Solve the following question:
In an electric circuit, two resistors of 12 0 each are joined in parallel to a 6 V battery. Find the current drawn from the battery.
How does the resistance of a metallic wire depend on the length of wire?
A piece of wire of resistance R is cut into three equal parts. These parts are then connected in parallel. If the equivalent resistance of this parallel combination is R1, what is the value of the ratio R1 : R?
