2022 CHIJ Phy Prelims P3 Ans

2022 Sec 4E Physics Practical (6091/03) Question Answer Marks 1(a)(i) MMO Vo in the range 4.00 V to 5.00 V and to 2 decimal places with unit. [V] 1 1(a)(ii) MMO V1 < Vo and to the correct decimal place[2dp] with unit. [V] (allow ecf for dp and unit) I1 in the range 0.04 A to 0.12 A and to 2 decimal places with unit. [A] 1 1 1(a)(iii) ACE correct calculation of P1 to 2sf (or 3sf) with appropriate unit [W] 1 1(b)(i) MMO V2 < V1 and I2 > I1 1 1(b)(ii) ACE correct calculation of R with unit [Ω] 1 1(c) ACE correct calculation of Q with no units for proportion. 1 1(d) ACE • Set up apparatus as shown in Fig.1.4. • Move the boss upwards till the wooden rod cause the shaft to just stop moving. • Use a ruler to measure the extension of the spring. • Remove the string and the wooden rod. Place slotted mass on the spring till the same extension of the spring is obtained. • F = weight = mass x g 1 1 1(e) ACE Replace spring with a spring balance to measure the force directly OR Hang slotted mass on the shaft directly. 1

2 CHIJSec/2018/OLevelPrelim/6091/03 Question Answer Marks 2(a) MMO h measured to correct precision and unit. h = 5.1 cm 2(b) MMO Average of at least 2 sets of timing used to obtain to sensible to with units (~2.80s to 2 dp) 1 1 2(c) ACE correct calculation of average speed vo to 3sf with unit [cm/s] 1 2(d) ACE correct calculation of average speed v1 with unit [cm/s] distance = 50 cm used in calculation 1 2(e) ACE statement do not support the suggestion with evidence to support the statement. (value of vo ≠ v1) 1 2(f) P - identify correct variables to be kept constant [at least 2 different variables] ➔ distance travelled by the glass ball ➔ mass of glass ball ➔ surface of rule ➔ initial speed of glass ball / force used to release glass ball - Description of experiment ➔ Release the glass ball at the 1 cm mark on the metres rules and immediately start the stopwatch. Stop the stopwatch when the glass ball reaches the end of the track ➔ Repeat the above step again to obtain another set of reading and calculate the average time taken, tave. ➔ Calculate the average speed, v. (average speed = 99 / time) ➔ Record the values in a table. ➔ Keeping key variables constant, repeat experiment for 4 different height h to obtain the respective time taken. (at least 5 sets of readings) - Table with headings - Plot a graph of average speed, v against height, h . - Verify the relationship h / cm t1 / s t2 / s tave / s v / cms-1 2 1 1 1

3 CHIJSec/2018/OLevelPrelim/6091/03 Question Answer Marks 3(a)(i) ACE Place the light source, object, lens and screen in a straight line. Move the lens until a blurred image in seen on the screen. By moving the lens towards the screen or tow