How to convert potatoes as voltaic cell?

 

 

potatoes can be used as cell or battery

 

introduction:

 

As per our knowledge, a cell is an electrical device which is used to convert chemical energy into electrical energy.  Hence, when we are using a cell, initially the chemical energy is utilized to produce electricity.  In a simple electrical circuit, we use to observe, a cell, connectors, a bulb like energy utilizer, and a switch.  When we close the circuit, that is by pressing the key, the current starts flowing through the conductors and bulb starts glowing, hence the closed electrical circuit can conduct the electricity, but all the closed circuits do not have electricity flow.  That means, the battery or cell should have chemical energy.  In our daily life, only cell alone can produce chemical energy or any natural substances can produce electricity? That is our discussion.  In this experiment, we are going to take potatoes as the producers of electricity.  The meaning is potatoes are used as cells or batteries. 

 

 

procedure:

 

The constituents of the cell are electrolyte, two electrodes anode and cathode, conductor wire, a bulb.  In a primary voltaic cell, dil. sulphuric acid is used as electrolyte, and zinc and copper plates act as electrodes.  Zinc acts as anode that is the electrons are migrated from zinc plate to copper plate through the dil. sulphuric acid solution.  Hence, copper plate acts as cathode, the potatoes acts like the solution of dil. sulphuric acid, zinc and copper plates are used for producing electricity from potatoes.

 

materials required:

 

1) 8 small potatoes, 2) 8 strips of copper and zinc 3) conductor (copper wire) 4) a bulb of 5v.

 

how to prepare a circuit?

 

In each potato, insert a zinc and copper strips, connect with wires, such that potato acts as electrolyte.  Hence, we should take care of the circuit such that it should be a closed circuit, in order to utilize the electrical energy, we should connect a bulb as energy consumer.  Use a table, to place all these materials and make visible. 

 

In between a bulb and wires, connect a switch to open or close the circuit.  Hence, we close the circuit by pressing the switch, current starts flowing and bulb starts glowing. 

 

alternative method:

one can use lemons instead of potatoes, replace the potatoes with lemons and the remaining connections are as usual.  Here, lemons are used as electrolyte. 

 

precautions:

 

1) don't insert two copper strips or zinc strips in a single potato or lemon.

2) don't connect wire to copper and zinc strip in the same potato.

3) make sure a series connection of arrangement.

 

 

 

 

 

 

 

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GEOMETRICAL OPTICS - BASIC CONCEPTS

INTRODUCTION:


What is light? Light is the energy emitted by the excited atoms which can cause the sensation of vision in a human eye, hence light is a form of radiant energy.


What is optics? The branch of physics which deals with the phenomena concerning light is called optics .

We can classify the optics into : 1) Geometrical optics 2) Physical optics.

What is Geometrical optics? The study involves, the light is considered as moving along a straight line as moving along straight line as a ray. A ray of light gives the direction of light. When the light meets a surface which separates two media, reflection and refraction take place.

What is Physical optics? Physical optics deals with the theories of light and explains all the phenomena such as reflection, refraction, interference, diffraction, polarisation, and rectilinear propagation.


Definitions:

a) a ray: A ray is nothing but, the path along which light travels is called a ray.

 b) a beam: A bundle of rays is called a beam.

 c) a pencil: A narrow beam is called a pencil of light

types of objects:

REAL OBJECTS: From a point, if two or more incident rays actually emanate or seem to emanate.

VIRTUAL OBJECT: If the rays are intercepted by an optical element, then the point of convergence is a virtual point behind the optical element.


 In general, we can say that an object is real when two rays emanate or diverge from a point, and an object is virtual when two incident rays seem to converge to that point

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making crystals

How to make crystals of a solution?

 

Introduction:

 One can identify that there is a definite shape to any crystal.  In this experiment, we can prepare a crystalline form of sodium chloride, copper sulphate or sodium nitrate or nickel sulphate. In any of the crystalline preparation, we should prepare a saturated solution.

 

materials required:  

 1) distilled water

2) plate

3) thread

4) a beaker of 200 ml

5) a glass rod

procedure: 

 Let us consider that we are going to prepare copper sulphate crystals, for that take some copper sulphate powder and mix it with hot water about 50 ml.  Make it a saturated solution, by stirring thoroughly with glass rod.  

Take the saturated solution of little quantity into a plate, and wait for certain time, till small crystals formed in the plate.  Using a thread, tie a fine crystal from it, and keep in the copper sulphate solution.   Wait for several days till the water gets evaporated from the beaker, we are going to observe that the seed crystal becomes larger crystal.

 

precautions:

 

1) don't disturb the solution 

2) wait for required time till crystal is formed.

3) stir the solution to make saturated solution

 

note: try to prepare some more crystallline structures of NaCl, etc. 

 

 

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making a clinometer

clinometer

How to make a clinometer?

 

 

 

 

introduction:

Generally, we use to measure an angle with the help of a protractor.  But, the protractor alone can't be used for measuring the height of building or a tree or a tower.  By using a clinometer, one can measure the height of any building or height of a tower, or height of a tower.  The clinometer is basically used by surveyors and engineers belongs to civil branch.  The clinometer consists of a weight attached to a piece of string hangs from the sighting device.  When the clinometer is tilted upward to view the top of the building, the string moves across a protractor like face and indicates the angle of inclination.  

construction of a clinometer:

materials required: 1 protractor, a piece of thread, 1 nail of length about 2.5 cm (for weight),

working procedure: Make a tiny hole at the center of the base line on the protractor, pass the taken thread through the hole, tie one end of the thread with nail, and another end should tie a knot in one end.  The angle shown by the nail is 90 degree when the protractor is held with its straight edge horizontal and upside. Now the clinometer is ready which can be used for measuring the height of a building or a tree.

How to find the heights?

step 1: Measure the distance from the place where you stand to the base of the building

step 2: To find the height of the building, You look along the top edge of the clinometer, focus to top of the building, allow the thread to move freely around the scale of the protractor.

step 3: The angle shown by the nail is equal to the angle which the building makes the horizon.

step 4: By using the formula, h=dtan(angle), by taking the value of the angle, and distance between you and the building, multiplying the tangent degree and distance, one can find the height of the building or a tower.

precautions:

1. take the angle properly.

2. distance should be measured accurately.

3. one can use a stand to fix the clinometer.

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A SENSOR TO IDENTIFY pH OF BLOOD

A TINY BLOOD pH SENSOR DEVELOPED BY INDIAN INSTITUTE OF TECHNOLOGY, KHARAGHPUR students

IIT Kharagpur researchers have successfully developed tiny device to measure the pH of blood.  The device works by measuring the imedance.  The device relies on venous blood sampling for pH measurement. 

The pH of a solution is a measure of the percentage  of hydrogen ions  available in a solution.  The solution is said to be  acidic, if  the pH will be less than 7.  The device was able to detect the pH of the blood in 10 seconds.

SOURCE: THE HINDU 

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states of matter

 


STATES OF MATTER : 

We use to observe that the matter will be in three states.  They are solid state, liquid state, and gaseous state. The state can be changed with the effect of pressure and temperature.  The temperature can be increased by increasing heat energy.  Heat energy is a different energy from other types of energies since, the heat is transmitted from higher temperature body to lower temperature body.  Whereas, the temperature is the intensity of the heat energy.  For example, when we touch an object, if we feel it is cold, the meaning is that the person who touched the object, the heat energy is transmitted from him/her to the object, then we feel very cool.  When we gain certain heat energy, we feel more hot.  In this way, the heat energy is the energy which is transferred only due to the differences in the temperatures or different intensities of heat energy.

SOLID STATE OF THE MATTER

If we observe, an ice cube, the water is in solid state.  In any solid state of a matter, the molecules or atoms are very close and we don't observe any space between each atoms.  There is no enough space between the atoms, there is a strong attractive force present between them.  No other particle can place in between the atoms of the solid substances.   

Due to these properties, solids have a definite shape, definite volume, definite mass.

LIQUID STATE OF THE MATTER

Water is an example for liquid state of the matter.  Liquids do not have a definite shape, but they posses definite volume.  Liquid state can be achieved by heating a solid state of the matter.  As we are increasing the temperature by supplying the heat energy, the atoms are going away from each other and they acquire space in between the atoms.  Hence, the strength of attraction is decreased, we can add some particles like sugar in between the atoms of the liquid. So, there is no definite shape.

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GASEOUS STATE OF THE MATTER

Water vapor is an example of the gaseous state of the matter, the atoms are very far away from each other, there is a lot of gap between the particles.  These gaseous particles move very easily and they can be compressed easily.  We can compress a large volume of gas in a cylinder.

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arithmetic reasoning questions

1) 121, 225,361,?
2) 9,11,20,31,?82
3)35,7,36,14,37,21,?
4)1,2,8,14,?,34
5)2,3,5,7,11,?17
6)3,12,27,48,75,108
7)2,1,2,4,4,5,6,7,8,8,10,11,?
8)2,5,26,677,?
9)0,7,26,63,?
10)2,15,4,80,?

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greatest common divisor

GCD

A divisor is another name of factor.  A factor is a number which divides a given number completely with leaving a reminder zero.

Let us find all the factors of 10

Number 10 is divided by 1,2,5,10, So these four numbers are the factors of 10.

Let us take another example of 20

Number 20 is divided by 1,2,4,5,10,20

Now we are going to find out the great common divisor of 10,20

let us take all the common factors of 10 & 20

1,2,5,10

Among the common factors of 10 & 20, the greatest number which is factor to both the 10, 20 is 10.

Hence the greatest common divisor of 10, 20 is 10.

The meaning is 10 is only the number which divides equally both 10,20.

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least common multiple

least common multiple is the lowest number among the common multiples of the given numbers


for example.....


finding LCM of 2,4
solution:


step 1... Write all multiples of 2 and 4
step 2.... Write all the common multiples
step 3....write the lowest of common multiples


then the answer is ...

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latest topics on physics

 1. states of matter
2. tiny blood pH sensor

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