A current of 2 A flows through a wire of cross-sectional area 25 . 0 mm 2 . The number of free electrons in a cubic meter are 2 . 0 × 10 28 . The drift velocity of the electrons is _____ × 10 - 6 ms - 1 (given, charge on electron = 1 . 6 × 10 - 19 C ).

Step-by-step solution

The drift velocity is given by v d = I n e A ⇒ I = n A e v d       . . . ( i ) The given data is I = 2   A A = 25 × 10 - 6   m 2 n = 2 × 10 28 e = 1 . 6 × 10 - 19   C Substituting the given values in equation (i) 2 = 2 × 10 28 × 25 × 10 − 6 × 1 .6 × 10 − 19 × v d ⇒ v d = 2 2 × 10 28 × 25 × 10 − 6 × 1 .6 × 10 − 19 ⇒ v d = 1 25 × 1 .6 × 1000   m   s - 1 = 25