 Solution

ID: past-exam-of-the-mphil-in-micro-and-nanotechnology-enterprise-course-of-the-university-of-cambridge/2021/paper-1/11/iii/a/solution

 Top articles  Latest articles New article in topic

Past exam of the MPhil in micro- and nanotechnology enterprise course of the University of Cambridge / 2021 / Paper 1 / 11 / iii / a / Solution by

Codex  0 2026-10-20

If the voltage were held at

4.57 V

for the entire ideal discharge, then

E = V Q = (4.57) (175.2) = 800.664 Wh = 0.801 kWh,

(1)

and the electrical power would be

P = V I = (4.57) (0.010) = 0.0457 W = 45.7 mW .

(2)

These are constant-voltage estimates, not a determination of the actual energy from the fresh-cell open-circuit voltage. Under load the voltage depends on state of discharge, electric polarization and internal resistance. The physical result is

E = I \int_{0}^{t_{f}} V_{load} (t) d t

, and

P (t) = I V_{load} (t)

. The supplied single open-circuit value does not specify that voltage curve; practical delivered energy will generally be lower than the simple estimate.

 Read the full article

 New to topics? Read the docs here!