EFFECT OF TEMPERATURE ON RESISTANCE, GSEB Physics practical std 8 to 12

Effect of Temperature on Resistance

EFFECT OF TEMPERATURE ON RESISTANCE

AIM :-

You are given a Wheatstone bridge, a container filled with a liquid, a resistor made from an iron wire etc. Immerse the resistor in liquid and connect it in an appropriate arm of Wheatstone bridge. Measure the resistance at different temperatures. Draw the graph of resistance versus temperature and from it find the resistance at 20⁰ c and 100⁰c. Use the following formula to determine(a ), the temperature coefficient of resistance.

Formula to calculate Effect of temperature on Resistance

PRINCIPLE  :-  On increasing the temperature of a conductor its resistance increases.

APPARATUS :- A coil of iron wire, container filled with liquid, a battery (2 V), a rheostat, a sensitive galvanometer, a simple key, a thermometer, a calorimeter, a burner, wire gauge, resistance box. 

Apparatus for Effect of Temperature on Resistance 

Practical Effect of Temperature on Resistance 

Procedure of Effect of Temperature on Resistance 

PRECAUTION :-               

(1)    Keep the iron cylinder completely immersed in liquid.

(2)    Keep all connections tight.

(3)    Stir the calorimeter for uniform heating of water. Note the temperature of the liquid immediately after the null point is obtained at every observations.

Graph of Effect of Temperature on Resistance

Draw the graph of R_t ® t. it is a linear graph. Extend this straight line on both the sides. Find R₂₀ and R₁₀₀ at the temperatures 20 ⁰C and 100 ⁰C respectively.

R₂₀  = …………… W at temperature 20 ⁰C

R₁₀₀ = …………… W at temperature 100 ⁰C

\     The temperature co-efficient of resistance of the given iron-wire is

RESULT :-  Temperature coefficient of resistance at given iron wire a = ………( ⁰c) ^-1

Beautiful Science Picture of Accessories use In Laboratory for students 8 to 12 std GSEB

Beautiful Science Accessories use in Laboratory.

Accessories used in Science Laboratory

Practical’s in chemistry and introduction of apparatus used

Before beginning the experiment in chemistry the student should have aware about

Principle,

Aim,

 Apparatus,

Chemicals used in experiments,

experimental method,

systematic note of  observation during the experiment chemical reactions and scientific conclusion.

                     

Apparatus used during the experiment :

            Test tube, Spatula, Tong, Stand, Test tube holder, Wire gauge, Tripod stand, Wash bottle, Measuring cylinder, Thistle funnel, Funnel, Distillation flask, Bunsen burner, Condenser, Watch glass, Dropper, Beaker, Conical flask, Evaporating dish etc.

During experiments, should not taste or drink solutions, nor touch or smell hot solutions or apparatus.

 If the need arises to smell, slowly and carefully do the same.

 Care should be taken to handle Bunsen burner.

 Glass rod should be used to stir the solution.

 Acid should always be added in the container containing water.

Test tube,

Spatula,

Tong,

Stand,

Test tube holder,

Tripod & wire gauge, 

Wash bottle, 

Measuring Cylinder,

Thistle funnel,

Funnel, Distillation flask,

Burner,

Condensor,

Watch glass,

Dropper,

Beaker,

Conical Flask, 

Evoparoting Dish,

Test tube

Spatula

Tong

Stand

Test tube Holder

Tripod stand and Wire gauge

Wash bottle

Measuring cylinder

Thistle funnel

Funnel

Distillation Flask

Bunsen Burner

Condenser

Watch Glass

Dropper

Beaker

Conical Flask

Evaporating dish

Post office box, principle of balanced Wheatstone bridge. physics practical std 11 & 12 GSEB

Post Office box

POST OFFICE BOX

Aim:-

A post office box and other necessary instruments are given to you. Take three appropriate ratios of the resistances in the two arms of Post Office Box and determine the values of two unknown resistances.

Now connect the unknown resistances in series and parallel respectively and verify the laws of series and parallel combinations of resistances.

PRINCIPLE :-

It works on the principle of balanced Wheatstone bridge.

APPARATUS :-

A Battery,

unknown resistance (Rx & Ry),

Post Office Box,

a galvanometer,

rheostat,

connecting wires

Post office box Apparatus

CONDITION  1 :- 

Connect unknown resistance      Rx between C and D

Post office line diagram condition 1

Post office condition 1 Practical

 CONDITION 2 :- 

Connect unknown resistance      Ry between C and D

 

Post office line diagram condition 2

Post office condition 2 practical

CONDITION 3 :- 

Connect unknown resistance      Rx & Ry in SERIES between C and D

Post office series connection 

Post office series connection practical

CONDITION 4 :- 

Connect unknown resistance      Rx & Ry in PARALLEL between C and D

Post office parallel connection condition 4

Post office box parallel connection 

Post office box observation table

Post office box calculations

Precautions

(1)   All plug keys of Post Office Box must be tight.

(2)    Contact points of K₁ and K₂ must be cleaned  with sand paper.

(3)    Galvanometer should be very sensitive.

(4)    Throughout the experiment  press key K₂(battery key) first and then key K₁(galvanometer key).

For more details view Video.

POST OFFICE BOX

Center punch for ITI fitter, Mechanic with animated video

Center Punch ITI Fitter

Center punch for ITI fitter, mechanic  with animated video.
Center punch for ITI fitter mechanical work.
It is made up of High Carbon Steel.

Center punch

Pointer angle 90 degree.

Center punch

Grind Center Punch.

Center punch use

Hold punch perpendicular to work piece

Center punch use and hammer stroke position

Work piece on which punching  is done

Hammer Stroke should be straight to the head of the punch.

Center punch use and hammer stroke position

Center punch use and hammer stroke position

You will get deep impression which is on punch shape in metal

Cross section of punch impression.

Center punch impression on metal

Cross section Center punch impression on metal

More details view video
Grinding process of Center Punch practical with video.

REFRACTIVE INDEX OF GLASS PRISM measure with Glass Prism for std 11 & 12 GBSE

Refractive index of  Glass Prism

REFRACTIVE INDEX OF GLASS PRISM 

12.2  AIM :-

Using pins with a given prism determine the angles of deviation for six different values of angle of incidence. Draw the graph of angle of deviation versus angle of incidence. Determine, from this the angle of minimum deviation and using following formula determine refractive index of material of the prism.

Formula for Refractive index of Glass Prism

Angle of prism, A = ……. .

APPARATUS:  Glass Prism, Drawing paper, Drawing board, Pencil, Ruler, Pin, Protector,

FORMULA : - A + d = i + e

PROCEDURE :-

Take paper and pin it on Drawing board. 

Now take Glass prism and put it on center of Drawing board paper.

Mark the edges of the prism with pencil

Refractive index of  Glass Prism procedure

Draw N₁Q perpendicular to AB

Draw a line PQ making an angle i of 35^O with N₁Q

NOTE :- Pins should be 3 – 4 cm. away from each other.

Fix two pins vertically on line PQ  at point L & M.

Refractive index of  Glass Prism procedure

Place the prism in its original position.

Refraction takes place QR after placing prism on its original place

Now look from surface AC, adjust pin N & O vertically on the side which you are looking so that the images of the pins L & M and the pin N & O appear to be in the same straight line.

Refractive index of  Glass Prism procedure

Draw a line  SR

Measure d = Ð UDN

Refractive index of  Glass Prism procedure

Draw a line SR, and draw a perpendicular N₂R at R to the line AC

Measure  e (Angle of Deviation)

Refractive index of  Glass Prism procedure

Refractive index of  Glass Prism procedure

Note :- Repeat the experiment by taking different angles of incidence viz.,

 40 ⁰, 45 ⁰, 50 ⁰, 55 ⁰ and 60 ⁰.

For more details View Video

Angle of Deviation.