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प्रश्न
Define the term resistivity and state its S.I. unit. Which will have higher resistivity a conductor or an insulator.
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उत्तर
The resistivity of a substance is the resistance of a wire of that substance of unit length and unit area of cross-section. Its S. I. unit is ohm × m. An insulator will have higher resistivity.
संबंधित प्रश्न
If the equivalent resistance is to be increased, then the number of resistances should be connected in
- Series
- Parallel
- Mixed arrangement
- None of the above
Find the equivalent resistance between points A and B.
The diagram below shows part of a circuit:
If this arrangement of three resistors was to be replaced by a single resistor, its resistance should be:
(a) 9 Ω
(b) 4 Ω
(c) 6 Ω
(d) 18 Ω
In series combination of resistances ______.
How will you oonnect five resistors, each of the value one ohm, to obtain an equivalent resistance of 0.2 `Omega`
Three resistors of 6.0 Ω, 2.0 Ω and 4.0 Ω are joined to an ammeter A and a cell of emf 6.0 V as shown in the following figure. Calculate :
- the effective resistance of the circuit.
- the reading of ammeter.
How does the resistance of an alloy, vary with temperature?
What material is used for making wire to prepare heating coils? Give a reason.
State expression for Cells connected in parallel.
