**ALTERNATIVE R**

UNIVERSITIES OF** **MANCHESTER
LIVERPOOL

LEEDS SHEFFIELD AND BIRMINGHAM

**JOINT
MATRICULATION BOARD**

**________________________________**

GENERAL CERTIFICATE OF** **EDUCATION

**PHYSICS—Paper III**

ADVANCED

Tuesday 15 June 1965 9.30 -
12.30

**Careless and untidy work will be
penalized**.

*Answer ***two** *questions*

*Choose three of the following questions. The Supervisor will inform you
which two of these you are to answer. The third is not to be answered.*

*When sets of apparatus are given distinguishing letters or numbers, these
letters or numbers must be given at the beginning of the answers.*

**All** **observations must** **be entered in ink
in the answer-book. All rough work must be done in the answer-book. No extra
paper may be used.**

*Detailed descriptions of the experiments performed are not required, but
labelled diagrams of the arrangement of the apparatus should be given and any
precautions taken to reduce errors should be indicated.*

*2 sheets of graph paper *are *supplied. Additional sheets will be supplied on
request but ***all ***sheets issued must be placed within the
answer-book and handed in to the Supervisor.*

*Mathematical tables are supplied.*

**95 ADV.** **ww ***Turn over*

**R1. **You are provided with five steel
spheres and some paraffin and are required to find the density of the steel and
of the paraffin.

Weigh
each sphere of mass *m *and measure its diameter *d. *Plot a graph having *m* as ordinate and _{}* ^{ }*as abscissa. Find the gradient of the graph. Hence deduce the density of
the steel.

Now weigh the largest sphere
completely immersed in paraffin. Hence deduce the density of the paraffin.

**R2.** Arrange an illuminated object,
a convex lens and a screen so that an image is focussed on the screen. Keeping
the object and screen fixed, move the lens until the image is again in focus on
the screen. Measure the displacement *d *of the lens and the distance *D
*between the object and screen. Repeat for four more values of *D.*

P1ot
a** **graph having_{}as ordinate and *D *as
abscissa. Find the gradient of the graph. Also deduce the focal length of the
lens from the graph.

**R3. **Apply the method of mixtures to
determine the specific heat of liquid paraffin.

Use
a 50 gm. brass mass as the hot body and about 100 gm. of the liquid paraffin in
the calorimeter. Take the temperature of the calorimeter and its contents at
intervals before, during and after the mixing and plot a graph with temperature
as ordinate and time as abscissa. Use this graph to make some allowance for
heat exchange between the calorimeter and its surroundings. Assume that the
specific heat of brass is 0.090 cal. gm.^{-1} deg.^{-1} C. The
specific heat of the material of the calorimeter will be supplied.

95 ADV

3

**R4. **Connect a length *x* of the
uniform wire *A *in one arm of a metre bridge and a standard resistance in
the other arm. Balance the bridge and measure the distance *y* of the
balance point from the end of the bridge wire adjacent to *A*.* *Repeat
for five more values of *x*.

Plot a graph having 1*/y *as
ordinate and l/*x* as abscissa. Find the gradient of the graph. Hence
deduce the resistance per unit length of *A.*

*95 *ADV.