Free KCSE Physics Topical Questions KNEC Standards

K.C.S.E Physics Q & A - MODEL 2019PP1QN16

31/7/2020

K.C.S.E Physics Q & A - MODEL 2019PP1QN16

(a) State the meaning of the term “heat capacity.”
(b) State how pressure affects the melting point of a substance.
(c)Figure 7 shows a set tip of apparatus that may be used to apparatus the specific latent heat of vaporization of steam

(I) Describe how the mass of condensed steam is determined.
(ii) Other than mass and time, state two other measurements that should be taken during the experiment.
(iii) Show how the measurements in (c)(ii) can be used to determine the specific latent heat of vaporization of water.
(iv) State the precaution that should be taken so that the mass of the condensed steam measured corresponds to the actual mass of steam collected during the time recorded in the experiment
(v) State why it is not necessary to measure temperature in in the set up

answers

(a) Heat capacity is the quantity of heat energy required to raise the temperature of a substance by 1K.
(b) - Increase in pressure lowers the melting point while decrease in (1 mark) pressure raises/increases the melting point.
(c) (i) - Measure the mass of the empty beaker M1.
Measure the mass of the beaker plus the condensed steam M2
Get the difference between the two masses (M2 —M1) = M
(ii) - Voltage
Current

(iv) - Start timing when the steam drops start forming out steadily and Stop immediately the beaker is withdrawn.
(V) Steam is produced at boiling point where temperature is constant.

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K.C.S.E Physics Q & A - MODEL 2018PP1QN14

29/7/2020

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K.C.S.E Physics Q & A - MODEL 2018PP1QN14

(a) State two differences between boiling and evaporation.
(b) State three ways in which loss of heat by conduction is minimized in a vacuum flask.
(c) In a certain experiment, 50g of dry steam at 100 °C was directed into some crushed ice at 0 °C. (Latent heal of vaporization of water is 2.26 X 106 Jkg-1, latent heat of fusion for ice is 3.34 X 10⁵ Jkg^-1 and specific heat capacity of water is 4.2 X 10³ Jkg^-1)
Determine the;

(i) quantity of heat lost by steam to change to water at 100 °C.
(ii) quantity of heat lost by water to cool to 0°C.
(iii) mass of ice melted at 0°C.

answers

(a) Boiling takes place at fixed temperature while evaporation takes at all temperatures.
Boiling takes place in the entire liquid while evaporation takes place at the surface.
(b) - Presence of a vacuum.
- Poor conductor material used to make stopper.
- Use of glass (poor conductor).

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K.C.S.E Physics Q & A - MODEL 2017PP1QN11

28/7/2020

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K.C.S.E Physics Q & A - MODEL 2017PP1QN11

A student who wanted to take a bath mixed 4 kg of water at 80 ^oc with 6 kg of water at 20 ^oc.
Determine the final temperature of the water.

answer

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K.C.S.E Physics Q & A - MODEL 2016PP1QN14

27/7/2020

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K.C.S.E Physics Q & A - MODEL 2016PP1QN14

a) Explain why it is advisable to use a pressure cooker for cooking at high altitudes

b) Water of mass 3.0kg initially at 20⁰C is heated in an electric kettle rated 3.0KW. The water is heated until it boils at 100⁰C. (Take specific heat capacity of water 4200Jkg1K^-1. Heat capacity of the kettle = 450JK^-1, Specific latent heat of vaporization of water = 2.3Mjkg^-1)

Determine
(i) The heat absorbed by the water.
ii)Heat absorbed by the electric kettle
iii) The time taken for the water to boil
iv) How much longer it will take to boil away all the water.

ANSWERS

(a) At high altitudes pressure is low so boiling point is low
A pressure cooker increases pressure inside it which raises the boiling point hence faster cooking

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K.C.S.E Physics Q & A - MODEL 2015PP1QN16

24/7/2020

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K.C.S.E Physics Q & A - MODEL 2015PP1QN16

(a) Figure 10 shows an incomplete set up that can be used in an experiment to determine the specific heat capacity of a solid of mass m by electrical method.

(i)complete the diagram by inserting the missing components for the experiment to work.
(ii)Other than temperature, state three measurements that should be taken.
(iii) The final temperature was recorded as O. Write an expression that can be used to determine the specific heat capacity of the solid.
(b) State three ways of increasing the sensitivity of a liquid-in-glass thermometer

answers

(a) (i) ammeter in series
voltmeter in parallel
(ii) ammeter reading (current)
- voltmeter reading (voltage)
-time

(b) reduce the diameter of the bore
use a thin walled bulb
use a liquid with a high expansivity

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FORM I - PHYSICS SYLLABUS

Introduction to Physics (4 Lessons)
Measurements 1 (12 Lessons)
Force (16 Lessons)
Pressure (24 Lessons)
Particulate Nature of Matter (12 Lessons)
Thermal Expansion (12 Lessons)
Heat Transfer
Rectilinear Propagation of Light and Reflection at Plane Surface (16 Lessons)
Electrostatics (12 Lessons)
Cells and Simple Circuits (12 Lessons)

FORM II - PHYSICS SYLLABUS

Magnetism (12 Lessons)
Measurements II (16 Lessons)
Turning Effect of Force (10 Lessons)
Equilibrium Centre of Gravity (12 Lessons)
Reflection at Curved Surfaces (16 Lessons)
Magnetic Effect of Electric Current (18 Lessons)
Hooke's Law (8 Lessons)
Waves (14 Lessons)
Sound (12 Lessons)
Fluid Flow (14 Lessons)

FORM III - PHYSICS SYLLABUS

Linear Motion (20 Lessons)
Refraction of Light (20 Lessons)
Laws of Motion (15 Lessons)
Energy, Power and Machines (20 Lessons)
Current Electricity (20 Lessons)
Waves II(10 Lessons)
Electrostatics II (15 Lessons)
Heating Effect of Electric Current (10 Lessons)
Quantity of Heat (20 Lessons)
Gas Laws (15 Lessons)

FORM IV - PHYSICS SYLLABUS

Thin Lenses (20 Lessons)
Uniform Circular Motion (10 Lessons)
Floating and Sinking (15 Lessons)
Electromagnetic Spectrum (15 Lessons)
Electromagnetic Induction (20 Lessons)
Mains Electricity (10 Lessons)
Cathode Rays and Cathode Ray Tube (10 Lessons)
X-rays (8 Lessons)
Photoelectric Effect (15 Lessons)
Radioactivity (15 Lessons)
Electronics (10 Lessons)

K.C.S.E Physics Q & A - MODEL 2019PP1QN16

K.C.S.E Physics Q & A - MODEL 2019PP1QN16

K.C.S.E Physics Q & A - MODEL 2018PP1QN14

K.C.S.E Physics Q & A - MODEL 2018PP1QN14

(i) quantity of heat lost by steam to change to water at 100 °C.
(ii) quantity of heat lost by water to cool to 0°C.
(iii) mass of ice melted at 0°C.

K.C.S.E Physics Q & A - MODEL 2017PP1QN11

K.C.S.E Physics Q & A - MODEL 2017PP1QN11

A student who wanted to take a bath mixed 4 kg of water at 80 ^oc with 6 kg of water at 20 ^oc.
Determine the final temperature of the water.

K.C.S.E Physics Q & A - MODEL 2016PP1QN14

K.C.S.E Physics Q & A - MODEL 2016PP1QN14

b) Water of mass 3.0kg initially at 20⁰C is heated in an electric kettle rated 3.0KW. The water is heated until it boils at 100⁰C. (Take specific heat capacity of water 4200Jkg1K^-1. Heat capacity of the kettle = 450JK^-1, Specific latent heat of vaporization of water = 2.3Mjkg^-1)

K.C.S.E Physics Q & A - MODEL 2015PP1QN16

K.C.S.E Physics Q & A - MODEL 2015PP1QN16

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FORM III - PHYSICS SYLLABUS

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K.C.S.E Physics Q & A - MODEL 2019PP1QN16

K.C.S.E Physics Q & A - MODEL 2019PP1QN16

K.C.S.E Physics Q & A - MODEL 2018PP1QN14

K.C.S.E Physics Q & A - MODEL 2018PP1QN14

(i) quantity of heat lost by steam to change to water at 100 °C. (ii) quantity of heat lost by water to cool to 0°C. (iii) mass of ice melted at 0°C.

K.C.S.E Physics Q & A - MODEL 2017PP1QN11

K.C.S.E Physics Q & A - MODEL 2017PP1QN11

A student who wanted to take a bath mixed 4 kg of water at 80 oc with 6 kg of water at 20 oc. Determine the final temperature of the water.

K.C.S.E Physics Q & A - MODEL 2016PP1QN14

K.C.S.E Physics Q & A - MODEL 2016PP1QN14

b) Water of mass 3.0kg initially at 200C is heated in an electric kettle rated 3.0KW. The water is heated until it boils at 1000C. (Take specific heat capacity of water 4200Jkg1K-1. Heat capacity of the kettle = 450JK-1, Specific latent heat of vaporization of water = 2.3Mjkg-1)

K.C.S.E Physics Q & A - MODEL 2015PP1QN16

K.C.S.E Physics Q & A - MODEL 2015PP1QN16

Categories

FORM I - PHYSICS SYLLABUS

FORM II - PHYSICS SYLLABUS

FORM III - PHYSICS SYLLABUS

FORM IV - PHYSICS SYLLABUS

Archives

M.A Nyamoti

HIGH SCHOOL RESOURCES

PRIMARY SCHOOL RESOURCES 8-4-4

PRIMARY SCHOOL RESOURCES CBC

COLLEGE RESOURCES

FREE NOVELS

Send Us a Message

(i) quantity of heat lost by steam to change to water at 100 °C.
(ii) quantity of heat lost by water to cool to 0°C.
(iii) mass of ice melted at 0°C.

A student who wanted to take a bath mixed 4 kg of water at 80 ^oc with 6 kg of water at 20 ^oc.
Determine the final temperature of the water.

b) Water of mass 3.0kg initially at 20⁰C is heated in an electric kettle rated 3.0KW. The water is heated until it boils at 100⁰C. (Take specific heat capacity of water 4200Jkg1K^-1. Heat capacity of the kettle = 450JK^-1, Specific latent heat of vaporization of water = 2.3Mjkg^-1)