Q:If p represents radiation pressure, c represents speed of light and S represents radiation energy striking unit area per sec. The non-zero integers x, y, z such that p^{x} S^{y} c^{z} is dimensionless are

(a) x = 1, y = 1, z = 1

(b) x = –1, y = 1, z = 1

(c) x = 1, y = –1, z = 1

(d) x = 1, y = 1, z = –1

Ans: (c)