Question

Question 3.19: Choose the correct alternative: (a) Alloys of metals usually have (greater/less) resistivity than that of their constituent metals. (b) Alloys usually have much (lower/higher) temperature coefficients of resistance than pure metals. (c) The resistivity of the alloy manganin is nearly independent of/increases rapidly with increase of temperature. (d) The resistivity of a typical insulator (e.g., amber) is greater than that of a metal by a factor of the order of (10 22 /10 3 ).

Class 12 - Physics - Current Electricity Current Electricity Page-129

Answer 1

here friend's your answer is as follows:
a) greater
b)lower
c)increases
d)10 3

not sure but I hope it helps you a lot

thank you

Answer 2

(a) alloy of metals have $\bf{greater}$ resistivity than that of their constituent metals.

(b) alloy usually have much $\bf{lower}$ temperature coefficients of resistance than metals.

(c) the resistivity of the alloy manganin is nearly $\bf{independent}$ of increasing temperature.

(d) the resistivity of a typical insulator (e.g., Amber) is greater than that of a metal by a factor of the order $\bf{10^{22}}$.