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Investigatory Project in Physics for Class 10

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PROJECT 1: THE EMISSIVE POWER AND EMISSIVITY

 

Aim:

To study the emissive power and emissivity of a surface for different colours)

 

Materials and apparatus:

(i) Tin cans of same size with their outer surfaces including lids painted with different colours like black, white, red, etc.

(ii) Sensitive thermometer with least count 0.1 °C.

(iii) Stand, water etc.

Investigatory Project on Viscosity

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Investigatory Project on Viscosity

Aim:


Comparison of viscosities of different liquid by rising bubble method


Materials and Apparatus:


(i) a tall glass jar (measuring jar)

(ii) a large flask

(iii) a funnel

(iv) a clean narrow capillary tube (drawn tube)

(v) glass tubes

(vi) rubber tubes

(vii) pinch-cock

(viii) different transparent liquids (eg: water, clear kerosene oil, sodium chloride solution, dilute copper sulphate solution etc)

(ix) stopwatch etc.

Investigatory Project in Physics

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PROJECT 1 : THE DAMPED OSCILLATIONS

 

Aim:

Study of damping of a bar pendulum by fixing card board pieces of different sizes at its bottom

 

Materials and Apparatus:

(1) A metre scale as compound bar pendulum

(2) Card board discs (square, rectangular or circular discs) of different size

(3) Stop-watch, stand etc

 

Procedure:

A small hole is drilled near one of the end of the metre scale. A long needle is passed through the hole. The size of the needle should be such that the scale should oscillate freely about the needle. The needle is firmly clamped horizontally on a suitable stand. It is kept near the edge of a table so that the metre scale can oscillate infront of the edge. A card board disc of area ‘a’ is cut off. It is fixed near the bottom of the metre scale in such a way that when the scale oscillates, the plane of the disc is perpendicular to the direction of oscillation.

The equilibrium position of the scale is marked on the edge of the table. A small amplitude of oscillation is also marked. The bar pendulum is pulled upto this mark and released. Simultaneously the stop watch is started. When the pendulum comes to rest, the total time ‘t’ of oscillations is noted. The experiment is repeated a number of times and the average value of ‘t’ is taken. The experiment is repeated for card board discs of different area a keeping their centre of mass at the same position on the scale. A graph is drawn with the time ‘t’ of oscillation and the area ‘a’ of the discs.

 

PROJECT 2 : THE INERTIAL BALANCE

 

Aim:

To construct an inertial balance, calibrate and find the inertial mass of a body.

 

Material required:

(1) A hacksaw blade of length 30 to 50 cm

(2) A light scale pan

(3) A set of known weights and the body of unknown mass

(4) Stopwatch, knitting needle

 

Procedure:

The hacksaw blade is clamped horizontally with its flat sin lace vertically over table. A knitting needle is kept vertically infront of the free end of the blade. A scale pan of negligible weight is glued at the flat surface of the hack-saw blade near the free end.

A suitable mass m, say 20 g, is placed in the pan. The end of the hacksaw blade is displaced horizontally and released. The blade vibrates horizontally. So the acceleration due to gravity does not affect the oscillations. The period of oscillation T is determined. The experiment is repeated with mass 2m, 3m, ... in the pan.

T = 2π(m/k), where k is the force constant of the blade.

T2/m = a constant

A graph is drawn with T2 along the Y-axis and m along the X-axis. This is the calibration curve.

The body of unknown mass ‘x’ is placed in the pan and the period of oscillation ‘T' is determined. The inertial mass x of the body is noted from the graph. (The mass in should be selected depending on the length, width and thickness of the hacksaw blade so that the period may be determined accurately)


To find m and T2


PROJECT 3 : THE HELICAL SPRING

 

Aim:

To study the variation of spring constant k with its diameter by making helical springs of different diameters using thick copper or steel wire.

 

Materials and apparatus

(i) Thick copper or steel wire

(ii) Stand

(iii) Stopwatch

(iv) Weight hanger and slotted weights

(v) Cylindrical tubes of different diameters

 

Procedure

Helical springs of different diameters are made by winding the copper wire over cylindrical tubes of different diameters. The diameter D of the spring is determined by measuring the diameter of the tube using a vernier calipers. The spring constant k is determined by load - extension method. The reading are tabulated. A graph is drawn connecting k and D.

 

PROJECT 4 : THE CLEANSING EFFECT OF DETERGENT

 

Aim:

To study the comparative cleansing effect of different detergents by the study of capillary rise

 

Materials and apparatus:

(1) A capillary tube of uniform bore

(2) Beaker

(3) Stand

(4) Common balance

(5) Different detergents

(6) One holed cork

(7) Divider, scale etc

 

Theory

For a give capillary tube, the capillary rise of liquid in the tube is directly proportional to the surface tension of the liquid. The presence of the detergent in water reduces surface tension. For equally concentrated solution of different detergent in water, capillary rise is Minimum for the best detergent and maximum lot worst detergent.

 

Procedure

Equal masses of different detergents are taken by finding the mass of the detergent using physical balance. Equal volumes of distilled water are taken in different beakers. The detergents are dissolved in water. Thus different beakers contain different detergents having the same concentration. The beakers are labelled as A, B, C,…..

The capillary tube is cleaned first with an acid, then with an alkali and finally with water. It is then passed through a hole in a cork and is arranged vertically by suitable stand with its lower end dipping in the solution contained in the beaker marked A. The solution rises in the capillary tube up to certain height. Using a divider and a metre scale, the height h of the solution in the tube from the surface of the solution in the beaker is measured. The experiment is repeated with the other solutions also. The capillary tube should be thoroughly cleaned and rinsed in distilled water before dipping in fresh detergent solutions.

 

Observation

Result

The different detergents in the order of cleaning power are as follows.

(1)..... (2)..... (3)..... (4).....

 

PROJECT 5 : THE COEFFICIENT OF FRICTION

 

Aim:

To find the relationship between forces of static friction and normal reaction by plotting a suitable graph and to find the coefficient of friction between a wooden block and horizontal surface

 

Materials and Apparatus

A wooden block, a smooth frictionless pulley, a table with a smooth horizontal top surface, scale pan, weight box, string etc

 

Procedure

The weight of the wooden block and that of the scale pan are determined using a spring balance. One end of a light inextensible string is tied to the hook fixed to the wooden block. The other end of the string passes over the pulley and carries the scale pan which hangs freely in air. Ensure that the string between the block and the pulley is horizontal.

Some weights are placed in the scale pan. The weight in scale pan is so adjusted that on gently tapping the table, the wooden block just begins to slide. The weight of the scale pan together with the weight in the pan gives the force of limiting friction Fms. The normal reaction R is given by the weight W of the wooden block. The coefficient of static friction is calculated by the equation,

µ = Fms/W

A known weight P is placed on the wooden block. Now the normal reaction R becomes (W + P). The limiting friction Fms, is determined as explained above. The co-efficient of static friction is calculated by the equation,

µ = Fms /(W + P)

The experiment is repeated for different weights on the block. The mean value of coefficient of friction µ is calculated. A graph is drawn with limiting friction Fms along the y-axis and normal reaction R along the x-axis. The graph is a straight line. The slope of line is a measure of the coefficient of friction between the surfaces of the block and the table.

Observation

Weight of the block = W = ……g

Weight of the scale pan = w = ……g

Results

(i) The graph connecting limiting friction and the normal reaction is a straight line.

(ii) Coefficient of static friction µ between the block and the table

(a) by calculation, µ = ….

(b) from the graph µ = ….


Note: Effect of lubricants on friction can be studied by performing the above experiment with lubricant between the surface of the block and the table in contact.

Investigatory Project on Diseases of Crop Plants

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A Study of Diseases of Crop Plants of a Particular Area

Introduction

 

The plant diseases may be defined as any abnormal physiological or morphological condition which causes a marked disturbance in the plants as a whole or any part of it, induced by certain external agencies. The most important agents which lead to diseases are unfavorable environmental conditions, deficiency of some elements, pathogens etc. Pathogens are the organisms which cause diseases. The various plant diseases delimit the normal growth of crop plants.

Investigatory Project on Medicinal Plants

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A Survey of Medicinal Plants of an Area

Introduction:


The history of medicinal plants is closely associated with the history of Botany. In India, Ayurvedic medicines have been in use for over 3000 years. Records of early civilisation in almost all parts of the world reveal that a great majority of drugs used in modern medicine were in use since ancient times. Practice of Ayurveda involves the application of herbal medications. Charaka is considered as the father of Ayurveda.

Investigatory Project on Fruits

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Investigatory Project - A Survey of different types of Fruits


          

Introduction : The ripened ovary of a flower is called fruit. After fertilization ovary develops into fruits and ovule develops into seeds. The fruits which develop from the ovary are called “true fruits”. Eg. Mango, bean etc. But in some case the fruits develop from other part of the flower except the ovary. They are called "false fruits” or Pseudocarp. Eg. Apple, cashew etc. The fruit wall is called pericarp. In fleshy fruit pericarp has 3 layers epicarp, mesocarp and endocarp. On the basis of origin and development the fruits are classified into three types. The three types of those fruits are simple fruits, aggregate fruits and multiple fruits. The study of fruits and its cultivation is called Pomology, which is a branch of Horticulture.

 

Materials and Methods : The following materials were collected first – bags, scissors, blade, tag and knife. Different local areas were selected for this study. The collection trips were arranged in different times of the year for fruit collection. The collected materials were tagged separately and kept in a bag for further studies. Then identified the plants and assessed the use of each fruit. All the details about the collected fruits were studied with the help of authentic text books.

 

Observation and Results : The collected fruits were observed carefully and identified the different types of fruits and then categorized them accordingly. Uses of each fruits were also recorded separately as follows.

 

1. Mango 

Botanical Name – Mangifera Indica 

Type of Fruit – True of fruit drupe 

Morphology of edible part – Mesocarp


2. Guava 

Botanical Name – Psidium Guayava 

Type of Fruit – True Berry 

Morphology of edible part – Thalamus and Pericarp


3. Tamarind 

Botanical Name – Tamarindus Indica 

Type of Fruit – True Berry 

Morphology of edible part – Seed Covering


4. Papaya 

Botanical Name – Carica Papaya 

Type of Fruit – True Berry 

Morphology of edible part – Mesocarp


5. Pine Apple 

Botanical Name – Ananas Comosus 

Type of Fruit – True Berry 

Morphology of edible part – Fleshy Pericarp


6. Cashew Nut 

Botanical Name – Anacardium Occidentale 

Type of Fruit – False Fruit 

Morphology of edible part – Thalamus


7. Grape 

Botanical Name – Vitis Vinifera 

Type of Fruit – True Fruit 

Morphology of edible part – Mesocarp


8. Banana 

Botanical Name – Musa Paradisiaca 

Type of Fruit – True Fruit 

Morphology of edible part – Mesocarp


9. Tomato 

Botanical Name – Lycopersicon Esculentum 

Type of Fruit – True Fruit 

Morphology of edible part – Mesocarp and Placenta


10. Orange 

Botanical Name – Citrus Aurentium 

Type of Fruit – True Fruit 

Morphology of edible part – Juicy Placental hairs


11. Wild Jack Fruit 

Botanical Name – Artocarpus Hirsuta 

Type of Fruit – True Fruit 

Morphology of edible part – Perianth Lobes


12. Jack Fruit 

Botanical Name – Artocarpus Heterophylla 

Type of Fruit – True Fruit 

Morphology of edible part – Perianth Lobes


13. Apple 

Botanical Name – Pyrus Malus 

Type of Fruit – False Fruit 

Morphology of edible part – Thalamus

 

Discussions and Conclusions : In this study an attempt has been made to study the nature, structure, functions and uses of each fruit. Most of the fruits were seasonal. Types of fruits (True or false), their local names and scientific names were also studied and recorded. The fruit includes berries (Grapes, banana & tomato), hesperidium (Orange), Drupe (Mango), Nut (Anacardium), sorosis (Jackfruit) and etaerio of berries (Custard apple).

The edible parts of fruits were different in different fruits. In mango and custard apple, mesocarp were edible. In apple, fleshy thalamus were edible. The present study of different fruits had revealed the fact that the diversity of nature was directly reflected in these edible fruits.

 

Viva Questions about A Survey of different types of Fruits

 

1. Distinguish between true fruits and false fruits.


Ans: Fruits that develop from the ovary are called true fruits and fruits that develop from any part of flower except ovary are called false fruit.


2. Name a false fruit


Ans: Apple


3. Name a dry indehiscent fruit


Ans: Cashew nut