तॉबे चाँदी और मैंगनिन की प्रतिरोधकता क्रमश: `1.7 xx 10^(-8) Omega- m 1.0 xx 10^(-8) Omega`एवं `44xx 10^(-8) Omega m ` है इनमे से सबसे अच्छा चालक कौन है।

The electrical resistivities of four materials A, B, C and D are given below: A : 110 xx 10^(-8) Omega m B : 1.0 xx 10^10 Omega m C : 10.0 xx 10^(-8) Omegam D : 2.3 xx 10^3 Omega m Which material is a (a) good conductor (b) resistor (c) insulator (d) semi-conductor?

If 4003250 = 4 xx 10^(x) + 3 xx 10^(7) + 2 xx 10^(z) + 5 xx 10^(w) , then x + y + z + w is equal to

(a) What is meant by saying that the potential difference two points is 1 volt ? Name a device that helps to measure the potential difference across a conductor. (b) Why does the connecting cord of an electric heater not glow hot while the heating element does ? ( c) Electrical resistivities of some substances at 20^@ C are given below : Silver 1.60 xx 10^-8 Omega m Copper 1.62 xx 10^-8 Omega m Tungsten 5.20 xx 10^-8 Omega m Iron 10.0 xx 10^-8 Omega m Mercury 94.0 xx 10^-8 Omega m Nichrome 100 xx 10^-6 Omega m . Answer the following question in relation to them : (i) Among silver and copper, which one is a better conductor ? Why ? (ii) Which material would you advise to be used in electrical heating devices ? Why ?

The electrical resistivities of five substances A,B,C,D and E are given below: {:(A,,5.20 xx 10^(-8)Omega m),(B,,110 xx 10^(-8) Omega m),(C,, 2.60 xx 10^(-8) Omega m),(D,,10.0 xx 10^(-8) Omega m),(E,,1.70 xx 10^(-8) Omega m):} (a) Which substance is the best conductor of electricity? why? (b) Which one is a better conductor: A or C? Why? (c) Which substance would you advise to be used for making heating elements of electric irons? Why? (d) Which two substances should be used for making electric wires? Why?

Resistivities of copper, silver and manganin are 1.7 xx10^-8 Omega m, 1.0 xx 10^-8 Omega m and 44 xx 10^-8 Omega m respectively. Which of these is the best conductor?

The electrical resistivities of four materials A,B,C and D are given below: {:(A,,110 xx 10^(-8)Omegam),(B,,1.0 xx 10^(10) Omega m),(C,, 10.0 xx 10^(-8)Omega m),(D,,2.3xx 10^(3) Omega m):} Which material is: (a) good conductor (b) resistor (c) insulator, and (d) semiconductor?

The electrical resistivities of four materials P,Q,R and S are given below: {:(P,,6.84 xx 10^(-8) Omegam),(Q,,1.70 xx 10^(-8) Omega m),(R,,1.0 xx 10^(15) Omega m),(S,,11.0 xx 10^(-7)Omega m):} Which material will you use for making: (a) heating element of electric iron (b) connecting wire of electric iron (c) covering of connecting wires? Give reason for your choice in each case.

When a 40 Vm^(-1) electric field produced inside a conductor then 2 xx 10^(4) Am^(-2) curren density is established in it. Resistivity of the conducot is (1) 2 xx 10^(-3) Omega m (2) 4 xx 10^(-3) Omega m (3) 2 xx 10^(3)Omega m (4) 4 xx 10^(3) Omega m