Mock Exam Set 1 - Paper 3

[Maximum mark: 12]

1. Young's double slit experiment is used to determine the wavelength of a monochromatic light source.

   

   The separation between the two slits $d$ = 0.15 $\pm$ 0.01 mm.
   The distance between the double slit and the screen $D$ = 1.30 $\pm$ 0.05 m.
   The distance between the bright fringes $s$ = 3.2 $\pm$ 0.1 mm

   1. Explain why a double slit is used instead of two light sources. [2]
      

   2. Determine the wavelength of the light, including its uncertainty. [3]
      

   3. The experiment is repeated with a larger distance $D$ but the same measurement tools were used.

      State and explain the impact of this change on the uncertainty on the calculated value for wavelength. [3]
      

2. 1. The experiment was repeated by changing the separation between the slits and the screen.

      The graph shows the variation of the distance between the bright fringes $s$ and the distance between the double slit and the screen $D$.

      

      Describe how the wavelength can be determined using the graph. You do not need to do the calculations. [2]
      

   2. State the effect of increasing the number of slits on the intensity of the fringes and on the experimental result for the wavelength. [2]
      

[Maximum mark: 9]

1. The circuit shown is used to measure the variation of the resistance R of a wire with the length L of the wire. The wire is connected across points $X$ and $Y$.

   $\footnotesize{\textrm{[Source: Created with GeoGebra by Tom Walsh - http:// ophysics.com/t1.html]}}$

   A voltmeter and an ammeter are connected to the circuit in order to investigate the relationship.

   1. Draw the ammeter and voltmeter on the given circuit with their correct connections. [2]
      

   2. State the purpose of connecting a resistor in series with the wire as shown in the diagram. [1]
      

2. The diameter d of the wire is kept constant at $d=0.58\pm0.01 \ mm$. Determine the percentage uncertainty of the cross sectional area A of the wire. [2]
   

3. The graph shows the variation of resistance of the wire R with the wire's length L.

   

   1. Draw the line of best fit. [1]
      

   2. Use the graph to estimate the resistivity of the wire. [3]