Use of Techniques, Apparatus and Materials

Fig. 2.2 is on page 5 of your question paper. On Fig. 2.2,

(i) draw a normal to the line XY at the point M and below the line XY,

(ii) draw a line from M at an angle of $40^\circ$ to the normal, towards the bottom left-hand side of the page. Label this line L.

Place the front surface of the mirror along the line XY with the reflective surface facing the bottom of the page. Position the light source and slit so that a ray of light passes along the line L towards M.

Remove the mirror. Draw a line through $P_1$ and $P_2$ that extends above XY. Label this line $R_1$.

On Fig. 2.2, draw a line through M at an angle of $20^\circ$ to the line XY, as shown in Fig. 2.1. Place the front of the mirror along this new line with the reflective surface facing the bottom of the page. Again position the light source and slit so that a ray of light passes along line L towards M.

Draw a line through $P_3$ and $P_4$ that meets the line $R_1$. Label this line $R_2$.

(i) On Fig. 2.1, draw a normal to the line XY at the point M, towards the bottom of the page. The normal should be greater than 10.0 cm long.

(ii) Place Fig. 2.1 on top of the soft board or polystyrene tile. Place the front surface of the mirror along the line XY with the reflective surface facing the bottom of the page.

Place a pin at a distance of 10.0 cm from M along the normal. This is the object pin.

(iii) Mark the position of this pin on the page with the letter O.

You are to determine the position of two reflected rays and the position of the image as accurately as possible.

(i) Look at the image of the object pin from the bottom right-hand corner of the page. Without moving your head, place another pin in line with the image. This pin is a sighting pin.

Place a second sighting pin in line with the image and the first sighting pin.

Label the positions of the sighting pins on the page with the letters $\text{P}_1$ and $\text{P}_2$. Remove the sighting pins.

(ii) Look at the image from a different point on the page. Repeat (i) and label the positions of the sighting pins $\text{P}_3$ and $\text{P}_4$. Remove the sighting pins and mirror.

(iii) Draw a line connecting points $\text{P}_1$ and $\text{P}_2$ and extend the line so that it passes behind the position of the mirror. Also draw a line connecting points $\text{P}_3$ and $\text{P}_4$ and extend this line so that it intersects the line connecting points $\text{P}_1$ and $\text{P}_2$. Label the point of intersection I.

(iv) Measure and record the perpendicular distance $y$ from I to the line XY.

$y$ = ______

Some electrical symbols are shown in Fig. 2.1.

Using some or all of the symbols in Fig. 2.1, draw a circuit diagram of the circuit.

Describe how you can obtain steady voltmeter readings.

Some electrical symbols are shown in Fig. 2.1.

Draw a diagram of the circuit.

Describe the precaution you take to obtain a steady voltmeter reading when the thermistor is in iced water.

On Fig. 2.1, draw a normal to the line XY at point M. Extend the normal 8 cm above and 8 cm below the line XY.

On Fig. 2.1, draw a line from point M to the left of the normal above line XY so that the angle between the drawn line and the normal is $40^\circ$.

Label the top left-hand end of the line as point L.

Place the block with one of its long sides on the line XY.

The top left-hand side of the block should be at point X.

Draw the outline of the block on Fig. 2.1.

Do not remove the transparent block.

Using the illuminated slit, shine a narrow ray of light along the line LM.

Mark with small crosses (x) two points on the ray that emerges from the block.

Choose the position of the points so that the ray leaving the block can be drawn accurately.

Remove the glass block.

Join the marked crosses and extend the line to meet the lower end of the outline of the block.

Label the point where the line meets the block outline as point P.

Draw a straight line to join the points M and P.

Explain the method that you used to determine $V$.

Explain two precautions that you took to determine an accurate value for $V$.

1. ______
2. ______