You are provided with the following:

• A lens and a lens holder.
• A screen with cross wires
• A candle
• A metre rule.

Proceed as follows:

a) Arrange the lightened candle, the lens and the screen as shown in figure 2. Adjust the position of the screen until a sharp inverted image of the candle is formed on the screen.

Figure 2

1. Measure the image distance.

v = …………………………… cm (1mark)

ii) Determine the focal length of the lens using the formula f = (2marks)

……………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………..

b) Now arrange the lighted candle, the screen with cross wires and the lens as shown in figure 3. Ensure that the centre of the lens, the cross-wires, and the candle flame lie on the same horizontal line. The candle flames should be placed close to the cross-wires for better illumination.

Figure 3

1. Adjust the position of the lens until a sharp image of the cross-wire is formed on the screen next to the cross wires. (Hint: You have to rotate the lens slightly about a vertical axis so that the image of the cross-wires falls on the screen next to the cross-wires and not on the cross-wires.)

Measure the distance d, between the lens and the screen.

d = ----------------------------------------------- cm (1mark)

1. Determine the values of L and X:

1. L = (2marks)

………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………

1. X = (2marks)

………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………

Part B

You are provided with the following

• Amicrometer screw gauge (to be shared)
• A centre zero galvanometer
• A switch
• Connecting wires ( at least five with a crocodile clip on one end)
• A resistance wire mounted on a millimeter scale labelled AB
• A resistance wire labelled P
• A resistance wire labelled G
• a metre rule or half metre rule
• two dry cells and a cell holder

Proceed as follows:

c) Using the micrometer screw gauge provided, measure the diameter

1. D of wire P

D = _{---------------------}mm (1mark)

1. d of wire Q

d = _{-----------------------}mm (1mark)

d) Determine C₁, the value of the ratio

C₁ = _{-------------------------------------------------------------------------} (2marks)

e) Set up the circuit as shown in Figure 4. (Ensure that each of the wires P and Q is 50cm long.)

Figure 4

Close the switch. Using the clip at the free end of the wire from the Galvanometer, tap wire AB near end A and observe the deflection in the galvanometer.

ii) Then tap the wire near end B and again observe the deflection in the galvanometer

iii) Now tap the wire AB at various points between A and B to obtain a point K where there is no deflection in the galvanometer

1. Determine the length L₁, the distance from A to K

L₁ = _{…………………………}cm (1mark)

1. Determine the length L₂, the distance from B to K

L₂ =……………… cm (1mark)

f i) Given that the resistance R_Q of Q is 9.0 Ohms, determine the resistance R_p of P using the expression: (2marks)

………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………

ii) Determine the value of C₂, given that, (2marks)

C_{2 =}

………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………

iii) Compare the value of C₁, in part (b) with that of C₂ (1mark)

………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………

Transcribed Image Text:

Candle u = 30cm www. Lens Screen, L Candle u = 30cm www. Lens Screen, L

Answer rating: 100% (QA)

part 1 Using the above equipment you can perform an experiment to find the focal length of the lens ... View the full answer