SUGGESTED INVESTIGATORY PROJECTS (BY C.B.S.E) CLASS XII
1 To study various factors on which the internal resistance/emf of a cell depends. 2. To study the variations, in current flowing, in a circuit containing a LDR, because of a variation. (a) in the power of the incandescent lamp, used to 'illuminate' the LDR. (Keeping all the lamps at a fixed distance). (b) in the distance of a incandescent lamp, (of fixed power), used to 'illuminate' the LDR. 3. To find the refractive indices of (a) water (b) oil (transparent) using a plane mirror, a equiconvex lens, (made from a glass of known refractive index) and an adjustable object needle. 4. To design an appropriate logic gate combination for a given truth table. 5. To investigate the relation between the ratio of (i) output and input voltage and (ii) number of turns in the secondary coil and primary coil of a self designed transformer. 6. To investigate the dependence, of the angle of deviation, on the angle of incidence, using a hollow prism filled, one by one, with different transparent fluids. 7. To estimate the charge induced on each one of the two identical styro foam (or pith) balls suspended in a vertical plane by making use of Coulomb's law. 8. To set up a common base transistor circuit and to study its input and output characteristic and to calculate its current gain. 9. To study the factor, on which the self inductance, of a coil, depends, by observing the effect of this coil, when put in series with a resistor/(bulb) in a circuit fed up by an a.c. source of adjustable frequency. 10. To construct a switch using a transistor and to draw the graph between the input and output voltage and mark the cut-off, saturation and active regions. 11. To study the earth's magnatic field using a tangent galvanometer.
SUGGESTED INVESTIGATORY PROJECTS(BY GROUP MEMBERS)
Diffraction of light by blades When laser light incident on fine slit, made by lateral combination of two blades edges. The blades are at distance of one to two meter apart from the screen so light shows diffraction pattern. The variation in the intensity with distance observed.
Variation of resistance with length of conductor. After completing the circuit of ohms law the reading of voltmeter and ammeter noted for different length of conductors.The observations are tabulated for various length of the conductors and resistance .it will show resistsnce of conductos depends on its length.
Project-3. To investigate the factors on which the sensitivity of a Potentiometer depends on.
Project-4. To investigate the effect of refractive index of different optical medium in a hollow prism on the angle of deviation using laser.
Investigatory Project 5 AIM: To investigate the dependence, of the angle of deviation, on the angle of incidence, using a hollow prism filled, one by one, with different transparent fluids. Apparatus: hollow prism, different liquids, al pins, drawing board, thumb pins, white sheet etc. Procedure:-By filling the hollow prism by different liquids repeat the same procedure adopted in experiment of minimum deviation of glass prism. Conclusion:-Draw the conclusion based on angle of deviation obtained for different liquids.
Investigatory Project 6 AIM. To design an appropriate OR logic gate and to verify the truth table. Appartus:-A battery, cells, Bulb/LED, Switch Analog Circuit Diagram
Procedure First we have to assemble all apparatus then we will fix them one by one on a cardboard or plywood. We will connect a bulb/LED to a cell or a battery through two switches as shown in figure. When one of the switch either A or B is in ON position the bulb/LED will glow and we can easily verify the truth table of OR gate.
Projects 7 Aim: Study of Total internal Reflection. Requirements: A beaker, a stirrer,a laser light,a soap piece and a test tube. Procedure: Put water in the beaker and dissolve soap cake piece in it with the help of stirrer.The laser pass from bottom of the beaker to strike the top surface of the water.A spot will be observe on the roof as well as floor of the room.This shows the partial reflection and refraction of the laser light at the interface of two media. Now let the beam inclined to strike the top surface of the water and the angle of inclination is adjusted till spot is obtained on the floor itself and no spot is available on the roof.Repeat this part of the experiment with soap water poured in a test tube such that laser beam gets reflected in number of times within the test tube.
Aim:-Roget’s spiral for attraction between parallel currents. Requirements: -Stand, helical spring, connecting wires and mercury. Procedure:-Magnetic effects are generally smaller than electric effects. It would be like pulling a wire by a string going over a pulley to which a 50 mg weight is attached. The displacement of the wire would be quite unnoticeable. With the use of a soft spring, we can increase the effective length of the parallel current and by using mercury, we can make the displacement of even a few mm observable very dramatically. You will also need a constant-current supply giving a constant current of about 5 A. Take a soft spring whose natural period of oscillations is about 0.5 – 1s. Hang it vertically and attach a pointed tip to its lower end, as shown in thfigure here. Take some mercury in a dish and adjust thespring such that the tip is just above the mercury surface. Take the DC current source, connect one of its terminals to the upper end of the spring, and dip the other terminal in mercury. If the tip of the spring touches mercury, the circuit is completed through mercury. Let the DC source be put off to begin with. Let the tip be adjusted so that it just touches the mercury surface. Switch on the constant current supply, and watch the fascinating outcome. The spring shrinks with a jerk, the tip comes out of mercury (just by a mm or so), the circuit is broken, the current stops, the spring relaxes and tries to come back to its original position, the tip again touches mercury establishing a currentin the circuit, and the cycle continues with tick, tick, tick, . . . . In the beginning, you may require some small adjustments to get a good effect. Keep your face away from mercury vapours as they are poisonous. Do not inhale mercury vapours for long.