Ask a Doubt
Request a call back

Join NOW to get access to exclusive study material for best results

CBSE Class 10 Answered

electricity
Asked by | 08 Dec, 2008, 12:06: PM
answered-by-expert Expert Answer

The resistance of a wire R = ρ l/A
where ρ - resistivity of the wire(its constant for a material)
            l - Length of the wire
            A - area of the crossection

Now A = πr2 where r - radius of the cross section. If d is the diameter then  
r = d/2

Hence A = 1/4πd2

This implies R  1/A  R1/d2

i.e. if the diameter is doubled the resistance reduces to 1/4 of the original value.

Answered by | 08 Dec, 2008, 01:51: PM

Application Videos

Concept Videos

Multiple Choice Questions Practice Test
Answered Unanswered My Questions My Answers
CBSE 10 - Physics
find the new resistance of wire length l area of cross section A if it is folded 4 times
Asked by nandhikasugumar | 05 Oct, 2023, 04:01: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 10 - Physics
finding the net resistance  
question image
Asked by daniya062008 | 02 Oct, 2023, 08:25: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 10 - Physics
the resistance of a wire of 0.01 cm radius is 10 ohm.if the resistivity of the material of the wire is 50*10^-8 ohm meter find the length of the wire
Asked by prassanna.j | 03 Sep, 2023, 12:28: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 10 - Physics
Nichrome wire of length L and radius R has resistance 10 ohm.How would the resistance of the wire change when: only diameter of the wire is doubled?Justify 
Asked by prassanna.j | 03 Sep, 2023, 12:21: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 10 - Physics
The resistance of a resistor is kept constant and the potential difference across its two ends is decreased to half of its former value.State the change that will occur in the current through it.
Asked by prassanna.j | 03 Sep, 2023, 12:13: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 10 - Physics
A given length of a wire is doubled of itself and this process is repeated once again.By what factor does the resistance of the wire changes?
Asked by prassanna.j | 03 Sep, 2023, 12:11: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 10 - Physics
 A 6 ohm resistance is doubled by folding,what is the new resistance?
Asked by prassanna.j | 28 Aug, 2023, 09:49: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 10 - Physics
Pls answer fast... In a resistive circuit, if the current is increased to two times the percentage change in the amount of heat dissipated in the circuit would be a) 400% b) 300% c) 200% d) 100%
Asked by anubhutiupadhaya | 04 Mar, 2023, 03:16: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 10 - Physics
Equivalent resistance 
question image
Asked by praveenkumae975 | 06 Feb, 2023, 07:19: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 10 - Physics
Two wires of copper have the same length but cross-sectional area in the ratio of 3:1. The resistance of the thicker wire is 12 ohm. (a) Calculate the resistance of the thinner wire. (b) Find the equivalent resistance of both these wires, when they are connected (1) in series (ii) parallel (c) If both the wires are connected in parallel to a battery of 24 volt, then find out the ratio of heat produced in the thicker wire to the thinner wire identify the wire if both of them are connected to the same source for the same time duration.
Asked by swetalinasamantaray022 | 20 Jan, 2023, 10:54: AM
ANSWERED BY EXPERT ANSWERED BY EXPERT
My Class Videos Tests ₹ Plans Ask a Doubt
Grab Our Exam Special Offer-Enrol now!
×