## SOTIK DISTRICT PHYSICS PRACTICAL QUESTIONS

1.  You are provided with the following apparatus:-

• Micrometer screw gauge
• Vernier caliper
• Water in a beaker 1000ml(should be ½ full)
• Long test-tube
• Some dry sand
• Spatula
• Millimetre scale marked on a paper strip
• Some cellotape
• 6 ball bearings

Proceed as follows:-

(i) Measure and record the diameter d of one ball bearing using micrometer screw gauge

d = ____________________cm

(ii) Determine the volume V of the spherical ball bearing

V = ___________________cm3

(iii) Measure the inside diameter d of the test-tube using vernier caliper. Record it below:

d = __________________cm

(iv) Find the cross-section area A of the test tube

A = ____________ cm2

(b) (i) Place the millimeter scale along the height of the test tube so that the zero is at the bottom

(ii) Place the test-tube in the water carefully and add sand bit by bit until it floats while

vertically upright in the water as shown:-

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(iii) Note and record the height ho
of water level by use of attached millimeter scale

ho = ______________cm

(c) Add one ball bearing into the tube, note and record the new level h in the table of results below:

(d) Repeat step (c) with two, three, four, five & six ball bearings and record their corresponding h(cm).

Compute values of h-ho(cm) in the table below:-

 No. of Ball Bearing (N) Floating level h(cm) h – ho(cm) 1 2 3 4 5 6

(e) Plot a graph of h-ho(cm) against the number of ball bearings (N)

(f) Determine the slope S, of the graph

(g) Relative density Ps, of ball bearing is given by:

Ps = SA. Find Ps

V

2. PART I

You are provided with the following apparatus:-

• Rectangular glass block
• Four optical pins
• Plain paper
• Soft board
• Piece of cellotape

Proceed as follows:-

(a) (i) Use cellotape provided to hold the sheet of plain paper on the soft board

(ii) Place the glass block on the middle of plain paper and with a sharp pencil, draw its outline

ABCD as shown:-

1. (i) Construct the normal on side AB, but close to A. Use protractor and ruler to draw an

incident ray with an angle of incidence = 10o   (ii) Insert pins P1 and P2 along the path drawn. Viewing through the glass block on side CD,

locate P3 and P4 such that P3 P4 appear in line with images of P1 and P2

(iii) Produce P1P2 to obtain a lateral displacement as shown in the figure below:-

Measure angle of refraction r, and lateral displacement

(c) Repeat steps (b)(ii) and (b)(iii) for angles of incidence i = 20o, 30o, 40o, 50o and 60o. Tabulate   your results as shown in the table:- Note: (You must handover your workings on the plain paper with the question paper after the session)

 Angle of incidence i 20o 30o 40o 50o 60o Angle of refraction Lateral displacement

(d) Plot a graph of lateral displacement, d, against angle of refraction r

2.  PART II

You are provided with the following:-

• An ammeter (0- 1A)
• A voltmeter (0-2.5V or 0-5V)
• Two dry cells
• A mounted resistance wire
• Eight connecting wires, two with crocodile clips
• A three volts torch bulb in a bulb holder
• A cell holder
• A switch
• A jockey or a crocodile clip

(a) Set-up the apparatus as shown below:-

(b) With the jockey or crocodile clip at C, 30cm, 50cm and 70cm, record their corresponding

V1, V2 and V3

(c) Replace the voltmeter with a torch bulb and an ammeter. Connect in series as shown in the

circuit diagram:-

(d) Read and record the ammeter reading I1, I2 and I3 for the corresponding values of lengths:

1 = 30cm, I1 = _______________

2= 50cm, I1 = __________________

3= 70cm , I3 = ___________________

(e) (i) Determine voltage values across the bulb for lengths 30cm, 50cm and 70cm given that

V = 0.025L

(ii) Determine the average resistance of bulb during the experiment

## SOTIK DISTRICT PHYSICS PRACTICAL ANSWERS

1.  (i) d = 0.635cm 0.05

(ii) V = 4/3 (0.635)3 = 0.134cm3 0.13 allow 0.14

(iii) d = 1.68 0.01

(iv) A = r2 = 3.14 x (1.68)2 = 2.21 (2.21 – 2.30)

=

(b) (iii) ho = 8.6cm ±0.2cm 8.0

(d)

 N h h-ho 1 9.0 0.4 2 9.7 1.1 3 10.3 1.7 4 10.9 2.3 5 11.5 2.9 6 12.0 3.4

(1mk for mark for each h value upto a max. of 4mks )

1mk for atleast 5 correct differences

½ mk for 3 and 4 correct differences

2 or less correct differences 0mks

(e) Axes – must be labeled the units (mark both)

Scale – be simple & uniform *

Plotting = ½ mk for each correctly plotted points up to 2mks

> 4 correct plotted 2mks

> 2 & 3 correctly plotted 1mk

<2 correctly plotted 0mk

Line must pass at least 3 correctly plotted points

(f) S = 0.527cm – Identifying the pts on the graph

-Correct substitution ( ½ mk)

-Correct answer to 2d.p ( ½ mk)

(g) Os = 0.527 x 2.21 (correct sub

0.134

= 8.69 ( no units) (correct evaluation to 2d.p –

2. PART 1

(c)

 i 10o 20o 30o 40o 50o 60o r 8o 13o 18o 24o 30o 36o ±1o d 0.5 0.9 1.3 1.9 2.8 3.2 ±0.1cm

½ mk for each correct value of both r and d

(d)

• Axes (Quantity and units- 1mk)
• Scale (simple and uniform 1mk)
• Plotting ( ½ mk for each correctly plotted point up to 2mks)
• The graph’s curve as shown
• Maximum = 6mks
• Smooth curve with correct shape as shown 1mk

Note:- The workings on the plain paper must be seen before marking this section

2. Part II

(b) 1 = 30cm, V1 = 0.75 ± 0.05

2 = 50cm, V2 = 1.225

3 = 70cm , V3 = 1.75

(d) 1 = 30cm , I = 0.12A ± 0.01

2 = 50cm 2 = 0.16A

3 = 70cm F3 = 0.20A*STK*

e(i) V1 = 30 x 0.0025 = 0.75V

V2 = 50 x 0.025 = 1.25V

V3 = 70 x 0.025 = 1.75

3values of V correctly calculated 1mk

2 values of V correctly calculated ½ mk

0.01 value of V correctly calculated 0mk

(ii) R1 = V1 = 0.75 = 6.25

I1 0.12

R2 = V2 = 1.25 = 7.81

I2 0.16

R3 = V3 = 1.75 = 8.75

I3 0.2

3 values correctly calculated to 2d.p 1mk

2 values correctly calculated to 2d.p ½ mk

0 or 1 value correctly calculated to 2d.p 1mk 0mk

Average R = R1 + R2 + R3
= 6.25 + 7.85 + 8.75 = 22.85 = 7.617

3 3 3

Substitution of 3 values of R ½ mk

Correct evlauation of average R value to 3d.p ½ mk

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