Question

The momentum acquired by the electron in 10 cm of the wire when a current of 1 A starts to flow, is –

• A. 5.6 × 10^–13 kg m/s
• B. 5.6 × 10^–7 kg m/s
• C. 2.8 × 10^–13 kg m/s
• D. 2.8 × 10^–7 kg m/s

Answer 1

Answer: (A)

5.6 × 10^–13 kg m/s

Answer 2

No. of electron in length l

N = nAl, n ® electron density

momentum of all electron

P = Nmv_d

= nAlm

= $\frac { 10 \times 10 ^ { - 2 } \times 9.1 \times 10 ^ { - 31 } \times 1 } { 1.6 \times 10 ^ { - 19 } }$

= 5.6 × 10^–13 Kg m/s