Which of the following is an example of a non-contact force? MCQ with Answer and Explanation

Explanation:
Frequency = vibrations per second. 500 vibrations per second. In 2 min = 120 s, total vibrations = 500 × 120 = 60,000. Simple multiplication.

Explanation:
At C (centre of curvature), image is at C, real, inverted, same size. At F, image at infinity. Beyond C, between F and C, diminished. Object between F and C gives beyond C, enlarged.

Explanation:
Minimum deviation δ_m for a prism: n = sin[(A + δ_m)/2] / sin(A/2), where A is prism angle, n refractive index. Thus δ_m depends on both A and n. Since n varies with wavelength (dispersion), δ_m also depends on wavelength, but the primary dependencies are A and n. Memory tip: 'δ_m increases with A and n; used to measure n'. This optics formula application is frequently tested in competitive exams. Always recall that minimum deviation occurs when ray passes symmetrically through prism, a key condition for derivation.