Form 3 Physics Annual Exam 2025 St. Marie Eugenie Girls
PHYSICS FORM THREE ANNUAL EXAMINATION ST. MARIE EUGENIE GIRLS SECONDARY SCHOOL 2025
SECTION C (30 Marks)
Answer two (2) questions from this section
9. (a) Two bulbs when connected in parallel to 230V supply take 60W each. What is the total power consumed when they are connected in series with the same supply? (5 marks)
(b) Two electric bulbs marked 100W,220V and 200W,220V have tungsten filament of the same bulb. Which bulb will have thicker filament? (5 marks)
(c) An electric kettle has two heating elements. One brings water to boiling point in 10minutes and the other in 15minutes.If the two elements are connected in parallel, find the time taken to boil the water in the kettle. (5 marks)
10. (a) If two objects P and Q are supplied with the same quantity of heat, the temperature change in P is observed to be twice that in Suppose the masses of P and Q are the same, Determine the ratio of specific heat capacity of P to Q. (5 marks)
(b) The specific heat capacity of acetic acid is approximately half that of water. Suppose an equal mass of water at 200C and acetic acid at 800C are mixed in an insulated cup. What will the temperature of the mixture be at thermal equilibrium? (5 marks)
(c) A pan full of crashes ice at 00C is heated 167W heater. Assuming there is no heat loss, what mass of the ice will melt if the heater is switched on for 100s? (5 marks)
11. (a) A wire of length 1.2m and diameter 0.64mm has a resistance of 2.4Ω. Calculate the resistance of a wire of length 0.8m and diameter 0.32mm of the same material. (5 marks)
(b) The potential difference across the terminals of a cell is 1.1V when a current of 0.2A is being drawn from the cell. If the potential difference across the cell is 1.3V when a current of 0.1A is being drawn, determine internal resistance and electromotive force of a cell. (5 marks)
(c) The balance length of a potentiometer wire for a cell of emf, E1=1.63V is 85cm.If the cell is replaced by another one of emf, E2=1.07V, calculate the new balance length. (5 marks)
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