Question

please answer me fast lesson- electricity class 4 standard​

Answer 1

Explanation:

1. bcoz tungsten have a higher melting point so it don't melt in high temperature also

2. it is because alloy's have higher melting point and it is have more better qualities than metal's.

3.it is not used for domestic circuit's bcoz if one appliance breaks down the other appliances will still work

4. resistance is inversely proportional to the area or cross section

5. copper and aluminium can transfer electricity more efficiently and they have lower melting point so if excess current passes the connection break's and don't affect the appliance

Answer 2

Answer:

(a)- Because, tungsten is an alloy which has very high melting point and very high resistivity so it does not burn easily at a high temperature.

(b)- It is because resistivity of an alloy is more than that of metals which produces large amount of heat.

(c)- In series circuits voltage is divided. Each component of a series circuit receives a small voltage so the amount of current decreases and the device becomes hot and does not work properly. Hence, series arrangement is not used in domestic circuits.

(d)- Resistance (R) of a wire is inversely proportional to its area of cross-section (A), i.e. when area of cross section increases the resistance decreases or vice versa.

(e)- Copper and aluminium are good conductors of electricity also they have low resistivity. So they are usually used for electricity transmission.

Explanation:

HOPE IT HELPS..

FOLLOW ME GUYS.