Question

1. the increase in any one dimension of a solid is called

(a) linear expansion
(b) area expansion
(c) volume expansion
(d) none of the above

1. materials with large k are called........; those with small k are called.........

(a) quantum dragons and superconductors
(b) conductors and insulators
(c) ballistic materials and oxides
(d) none of the above

1. what is frequency of radiation with a wavelength of 442×10⁻⁹ m

(a) 6.78×10¹⁴ hz
(b) 3.0×10⁸ hz
(c) 442×10⁻⁹ hz
(d) none of the above

Explanation:

Step1: Recall definitions

• Linear expansion is the increase in one dimension (length) of a solid. Area expansion is increase in two - dimensional (area) and volume expansion is increase in three - dimensional (volume). So for question 22, linear expansion (a) is correct.
• For question 23, materials with large thermal conductivity \(k\) are conductors and those with small \(k\) are insulators.
• For question 24, use the formula \(c = \lambda f\) (where \(c = 3\times10^{8}\ m/s\) is the speed of light, \(\lambda\) is wavelength and \(f\) is frequency). Rearranging for \(f\) gives \(f=\frac{c}{\lambda}\). Substitute \(c = 3\times 10^{8}\ m/s\) and \(\lambda=442\times 10^{-9}\ m\). Then \(f=\frac{3\times 10^{8}}{442\times 10^{-9}}\approx6.78\times 10^{14}\ Hz\)

Answer:

1. (a) linear expansion
2. (b) conductors and insulators
3. (a) \(6.78\times 10^{14}\ Hz\)