Question

*Explain the following:*

a). why is the tungsten used almost exclusively for filament of electric lamps?

b). why are the conductors of electric heating devices, such as bread-toasters are electric irons, made of an alloy rather than a pure metal?


c). why is the series arrangement not used for domestic circuits?


d) how does the resistance of a wire vary with its area of cross-section?

Answer 1

Hi friend

(a) Because Tungsten is a free element. there very high melting point 3695K.lowest vapor pressure, and greatest tensile strength out of all the metals.

(b) Because Resistivity alloy is more that metal is produce large amount heat

(c) Because series circuit receive a small voltage and the amount current decrease .

(d) when area of cross section increase then resistance decrease.

Answer 2

==============ⓢⓦⓘⓖⓨ

$\bold\red{hello...frd\:swigy\:here}$

$\bold\green{Your\:Answer:-}$

a) The melting point and resistivity of tungsten are very high. It does not burn very esay at a high temperature. The electric lamps glow at very high temperatures. Hence, tungsten is mainly used as heating element of electric bulbs.

b) The conductors of electric heating devices such as bread toasters and electric irons are made of alloy because resistivity of an alloy is more than that of metals. It produces large amount of heat and do not burn easily.

c) series arrangement is not used in domestic circuits. Because

◾ There is voltage division in series circuits. Each component of a series circuit receives a small voltage for a large supply voltage. As a result, the amount of current decreases and the device becomes hot.

d) Resistance (R) of a wire is inversely proportional to its area of cross-section (A):

R∝1/ A

I hope, this will help you

Thank you____❤

✿┅═══❁✿ $\bold\green{BeHappy}$ ✿❁═══┅✿