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प्रश्न
How does the resistance of a metallic wire depend on the thickness of wire?
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उत्तर
The resistance of a wire decreases with increase in its thickness (R ∝ l/a where a = πr2, the area of cross-section of the wire).
संबंधित प्रश्न
An electric lamp of 100 Ω, a toaster of resistance 50 Ω, and a water filter of resistance 500 Ω are connected in parallel to a 220 V source. What is the resistance of an electric iron connected to the same source that takes as much current as all three appliances, and what is the current through it?
How many 176 Ω resistors (in parallel) are required to carry 5 A on a 220 V line?
An electric heater which is connected to a 220 V supply line has two resistance coils A and B of 24 Ω resistance each. These coils can be used separately (one at a time), in series or in parallel. Calculate the current drawn when:
(a) only one coil A is used.
(b) coils A and B are used in series.
(c) coils A and B are uses in parallel.
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 uniform wire with a resistance of 27 Ω is divided into three equal pieces and then they are joined in parallel. Find the equivalent resistance of the parallel combination.
A given wire is stretched to double its length. How will its resistance change?
In the figure below, the ammeter A reads 0.3 A. Calculate:
(i) the total resistance of the circuit
(ii) the value of R
(iii) the current flowing through R.
Two resistors having resistance 8 Ω and 12 Ω are connected in parallel. Find their equivalent resistance.
You have three resistors of values 2 Ω, 3 Ω, and 5 Ω. How will you join them so that the total resistance is less than 1 Ω? Draw a diagram and find the total resistance.
