Advertisements
Advertisements
प्रश्न
A wire of length 1 m and radius 0.1 mm has a resistance of 100 Ω. Find the resistivity of the material.
Advertisements
उत्तर
Let ρ be the resistivity of the wire.
Given:-
Length, l = 1 m
Radius, r = 0.1 × 10–3 m
Area, A = πr2
Resistance, R = 100 Ω
We know:-
`R = rho l/A`
⇒ `rho = (RA)/l`
= `(100 xx pi xx 0.1 xx 0.1 xx 10^-6)/1`
= `pi xx 10^-6 Omegam`
APPEARS IN
संबंधित प्रश्न
What conclusion can you draw from the following observations on a resistor made of alloy manganin?
| Current A |
Voltage V |
Current A |
Voltage V |
| 0.2 | 3.94 | 3.0 | 59.2 |
| 0.4 | 7.87 | 4.0 | 78.8 |
| 0.6 | 11.8 | 5.0 | 98.6 |
| 0.8 | 15.7 | 6.0 | 118.5 |
| 1.0 | 19.7 | 7.0 | 138.2 |
| 2.0 | 39.4 | 8.0 | 158.0 |
Choose the correct alternative:
Alloys of metals usually have (greater/less) resistivity than that of their constituent metals.
A heating element is marked 210 V, 630 W. What is the value of the current drawn by the element when connected to a 210 V dc source?
Two wires of equal length, one of copper and the other of manganin have the same resistance. Which wire is thicker?
Plot a graph showing the variation of stopping potential with the frequency of incident radiation for two different photosensitive materials having work functions W1 and W2 (W1 > W2). On what factors does the (i) slope and (ii) intercept of the lines depend?
A uniform wire of resistance 100 Ω is melted and recast as a wire whose length is double that of the original. What would be the resistance of the wire?
If R1 and R2 are filament resistances of a 200 W and a 100 W bulb respectively, designed to operate on the same voltage, then:
Choose the correct alternative:
The resistivity of the alloy manganin is nearly independent of/increases rapidly with increase of temperature.
Choose the correct alternative:
The resistivity of a typical insulator (e.g., amber) is greater than that of a metal by a factor of the order of (1022/1023).
The resistivity of alloy manganin is ______.
Fuse wire should have
