Two quantities A and B have different dimensions. Which mathematical operations may be physically meaningful ?

(i) A/B (ii) (A + B)

(iii) (A - B) (iv) A = B

(i) A/B may be physically meaningful.

(i) A/B (ii) (A + B)

(iii) (A - B) (iv) A = B

(i) A/B may be physically meaningful.