Advanced level 2023 south west regional mock physics 2

Advanced level 2023 south west regional mock physics 2

Advanced level 2023 south west regional mock physics 2

Einstein s Photo-electric equation is a homogeneous equation of the form B — & fa +
bv
, where B is the energy of the incident radiation on a clean metal surface, /0 is
the threshold frequency, v is the maximum speed of ejected electrons and a and b
are constants.
a) Explain the meaning of the underlined phrase
b) Determine the base units of a and b (5 marks) ‘J
2. The graph in figure 1 shows the variation of Af(c) with C, where N(c) is defined such
that /V(c)AC is the number of molecules with speeds between C and C + AC at a
temperature T.
N(c)/102? s m’1
Figure 1
4 3 2 1 0
Speed C/ 102 m s’1
3) Estimate the total number ofmolecules in the gas under investigation at the particular
temperature.
b) Determine from the graph, the most probable speed
c) Assuming that the most probable speed is equal to the r.m.s value, calculate the
temperature, T, of the gas, if the mass is 12 g (6 marks)
a) Distinguish clearly between diffraction and interference. ”
fi
b) Monochromatic light of wavelength 5.0 x 10“7m falls normally on a diffracting
grating which has 425 lines per millimetre.
What is the highest order of diffraction?
3.
1.
ii. Find the angular separation between the first and the third ordered li
marks)
4, A 70 \iF capacitor, a 0.3 H inductor and a 50 ft resistor are connected in
120 Vt 60 Hz power source as shown in figure 2