Electromagnetism — Question 260

ANSWER

(a) $-1.00\,\mathrm V$ for $0<t<10\,\mathrm{ms}$; $0$ for $10<t<30\,\mathrm{ms}$; $+0.500\,\mathrm V$ for $30<t<50\,\mathrm{ms}$. (b) Counterclockwise as viewed on the page.

Worked solution

(a) $\mathcal E=-N\Delta\Phi/\Delta t$. The flux slopes are $+0.0200$, $0$, and $-0.0100\,\mathrm{Wb\,s^{-1}}$. Multiplication by $-50$ gives the three horizontal EMF segments.

(b) Out-of-page flux is decreasing, so the induced current produces out-of-page field; the right-hand rule gives counterclockwise current.

Equivalent physically justified methods, alternative valid sketches and consistent units accepted.

Accept sensible significant figures and consistent rounding from stated constants.

Part a: Draw and label the first negative EMF segment.

[1 mark]

Part a: Draw the zero plateau interval.

[1 mark]

Part a: Draw and label the final positive EMF segment.

[1 mark]

Part b: Give counterclockwise with a consistent explanation or stated sign convention.

[1 mark]

Practice question aligned to the current QCAA syllabus; review the worked solution and marking criteria.