Quelpr
1 markAtomic Structure

CAPE Physics Unit 2 · May/June 2024 · Paper 2 · Question 3(e)(i)

The original Millikan experiment was performed in the presence of air which exerted a buoyancy force on the droplet.

State the direction of the buoyancy force.

The mark scheme is shown once you've answered.

Practise this question

Other parts of this question

  1. 3(a)Identify EACH of the components labelled A-F.[6 marks]
  2. 3(b)(i)Complete Column 3 of Table 2.[2 marks]
  3. 3(b)(ii)On the grid provided in Figure 5 on page 17, plot a graph of charge, Q, versus 1/V. Draw the line of best fit through the points.[4 marks]
  4. 3(b)(iii)Use the graph in (b)(ii) to determine a value for the constant, K.[4 marks]
  5. 3(c)(i)Write the equation expressing the equilibrium between the electrical force on a charge, Q, in a field of strength, E, and the gravitational force on a droplet…[1 mark]
  6. 3(c)(ii)Write the equation relating the magnitude of the electric field, E, to the impressed voltage, V, and plate separation, d.[1 mark]
  7. 3(c)(iii)Write the equation expressing the mass, m, of the droplets in terms of the radius and density.[1 mark]
  8. 3(d)(i)Show that Q is given by the equation Q = (1/V) [(4/3)πr³ρgd] by substituting the equations in (c)(ii) and (iii) into the equation stated in (c)(i).[2 marks]
  9. 3(d)(ii)Hence, deduce an expression for K.[1 mark]
  10. 3(d)(iii)Determine a value for the magnitude of K.[3 marks]
  11. 3(e)(ii)Calculate the magnitude of the buoyancy force given that the density of air is 1.3 kg m⁻³.[4 marks]

More practice: the rest of this paper · more Atomic Structure questions · all CAPE Physics Unit 2 past papers