Physics Paper 3 Questions with Confidential - Mokasa 1 Joint Pre Mocks Exams 2023

Instructions

• You are supposed to spend the first 15 minutes of the 2 ½ hours allowed for this paper reading the whole paper carefully before your start.
• Marks will be given for clear record of observations actually made, for their suitability and accuracy, and the use made of them.
• Candidates are advised to record their observations as soon as they are made.
• Electronic calculators and mathematical tables may be used.

QUESTION ONE

You are provided with;

• Triangular prism
• Four optical pins
• Four thumb pins
• Soft board
• Plain paper

PART A

Procedure as follows;

1. Place the triangular glass prism on a plain paper and draw its outline ABC. Remove the prism.
2. Measure the size of angle ABC using a protractor
   B…………………………………………. (1mk)
3. Draw a normal to the line AB at N. (Midway of AB)
4. Draw a line at an angle i= 55°and fix two optical pins P₁ and P₂ on the line
5. Replace the prism and fix two other pins P₃ and P₄ such that the pins appear to be in a straight line with the images of P₁ and P₂ when viewed from side BC.
6. Remove the prism and join points P₃ and P₄ producing the line to meet the incident line produced at m.
7. Draw another normal along BC at K as shown;
8. Measure and record the angle of emergence, e and that of deviation d.
9. Repeat the experiment with i= 50° and 45°
   
   (6mks)
   

   Angle i (°)	Angle d (°)	Angle e (°)
   55
   50
   45

   
   From your table,
10. State the minimum angle of deviation D
    D = ………………………………… (1mk)
11. Given that; (2mk)
    r = sin(^B/₂+^D/₂)
              sin ^B/₂
    find r.

PART B

You are provided with the following apparatus

• 20 paper clips
• Cork with an optical pin
• A complete retort stand
• A stop watch
• Electronic balance (may be shared)

Proceed as follows;

1. Using the beam balance, determine the mass of a paper clip, m
   M=………………………………………..g (1mk)
   Mass of 15 clips: mt
   M_t =………………………………………g (1mk)
2. Make a chain to consist of 10 paper clips ensuring the links are free to move.
3. Set up the pendulum of the chain of paper clips as shown below;
   
4. Displace the bottom link of the chain through small amplitude and release so that the chain swing smoothly in a vertical plane.
5. Time 20 oscillations and fill the table below.
6. Using the number of clips shown in the table, repeat the experiment and complete the table. (5mks)
   

   Number of clips	Time for 20 oscillation (s)	Period T (s)	T2(S2)
   10
   15
   20

7. Determine the average value of T2. (1mk)
8. Determine constant Ƶ given that: (2mk)
   150Ƶ = m_ts where s is the average of T²

QUESTION TWO

You are provided with the following

• 2 new dry cells in a cell holder
• At least 6 connecting wires
• Ammeter
• Voltmeter
• Rheostat
• Switch

Proceed as follows;

1. Set the apparatus as shown below.
   
2. Set the variable resistor R to its maximum value and record the voltmeter reading V.
   V=………………………………………. (1mk)
3. Adjust the voltage to values shown in the table, each at a time and record the corresponding ammeter reading for current. Complete the table. (6mks)
   

   Voltage (V)	2.5	2.0	1.8	1.5	1.3	1.0
   Current (A)

4. On the grid below, draw a graph of Voltage, V (V) against current, I (A) (5mks)
5. Determine the slope s, of your graph (3mks)
6. Given that E = (V + Ir); find the value of constant E and r. (3mks)
7. Draw a setup that maybe used to determine the E.M.F of the dry cells used (1mk)
8. Set up the apparatus as drawn and hence measure the E.M.F, E₂ of the dry cells (1mk)

CONFIDENTIAL

• Triangular prism
• Four optical pins
• Four thumb pins
• Soft board
• Plain paper
• 20 paper clips
• Cork with an optical pin
• A complete retort stand
• A stop watch
• Electronic balance (may be shared)
• 2 new dry cells in a cell holder
• At least 6 connecting wires
• Ammeter
• Voltmeter
• Rheostat
• Switch