<p>(a) Write the formula for determining the equivalent resistance between A and B of the two combinations (i) and (ii) of three resistors&nbsp;<math xmlns="http://www.w3.org/1998/Math/MathML"><msub><mi>R</mi><mn>1</mn></msub><mo>,</mo><mo>&#160;</mo><msub><mi>R</mi><mn>2</mn></msub><mo>&#160;</mo><mi>a</mi><mi>n</mi><mi>d</mi><mo>&#160;</mo><msub><mi>R</mi><mn>3</mn></msub></math>&nbsp;arranged as follows:</p>

<p><img alt="" src="https://school.achievam.com/upload/questionbank/question/que_1758594619.PNG" style="height:150px; width:175px" /></p>

<p>(b) If the equivalent resistance of the arrangements (i) and (ii) are&nbsp;<math xmlns="http://www.w3.org/1998/Math/MathML"><msub><mi>R</mi><mi>s</mi></msub><mo>&#160;</mo><mi>a</mi><mi>n</mi><mi>d</mi><mo>&#160;</mo><msub><mi>R</mi><mi>p</mi></msub></math>&nbsp;respectively, then which one of the following V-I graphs is correctly labelled? Justify your answer.</p>

<p><img alt="" src="https://school.achievam.com/upload/questionbank/question/que_1758594733.PNG" style="height:120px; width:227px" /></p>