CIE iGCSE Co-Ordinated Science P1.4 Density Exam Style Questions Paper 4
Question
A student investigates the properties of graphite.
(a) Fig. 3.1 shows a cylinder of graphite.
The cylinder is 6.50cm long and has a cross‐sectional area of 0.300cm$^{2}$.
(i) Show that the volume of the cylinder of graphite is 1.95cm$^{3}$.
(ii) The mass of the cylinder of graphite is 4.40g.
Calculate the density of graphite.
(b) The student investigates the resistance of the cylinder of graphite using the circuit shown in Fig. 3.2.
(i) State the reading shown on the voltmeter in Fig. 3.2.
(ii) The ammeter reads 0.60A.
Use your answer to (b)(i) to calculate the resistance of the cylinder of graphite.
(iii) A different cylinder of graphite has double the length and double the cross‐sectional area of the cylinder in Fig. 3.2.
Explain why the resistance of both cylinders is the same.
(c) Graphite is a solid at room temperature.
Describe the main method of thermal energy transfer in solids.
▶️Answer/Explanation
Ans : 3(a)(i) (volume =) 6.5(0) × 0.3(00) ;
3(a)(ii) evidence of $\rho$ =$ \frac{m}{V}$ or 4.4(0) ÷ 1.95 ;
2.26 (g/ cm$^{3}$ ) ;
3(b)(i) 1.5 (V) ;
3(b)(ii) evidence of R = V ÷ I or 1.5 ÷ 0.6(0) ;
2.5 (Ω) ;
3(b)(iii) (idea that) doubling the length doubles the resistance ;
(idea that) doubling the (cross-sectional) area halves the resistance ;
3(c) any two from:
atoms vibrate ;
(idea that) vibrations passed on to next atom ;
(idea of) transfer by (free) electrons ;