Page 9 - Physics - XII

Experiment - 5: To determine angle of minimum deviation for a given prism by plotting a graph 78
between angle of incidence and angle of deviation.
Experiment - 6: To determine refractive index of a glass slab using a travelling microscope. 80
Experiment - 7: To find the refractive index of a liquid using convex lens and plane mirror. 83
Experiment - 8. To find the refractive index of a liquid using a concave mirror and a plane mirror. 88

5. Semiconductor Electronics: Materials, Devices and Simple Circuits 96–104
Experiment - 9: To draw the I-V characteristic curve for a p-n junction diode in forward and reverse bias. 96

ACTIVITIES

Activity - 1. To identify a diode, an LED, a resistor and a capacitor from a mixed collection of such items. 105
Activity - 2: Use of multimeter to see the unidirectional flow of current in case of a diode and an LED and 106
check whether a given electronic component (e.g., diode) is in working order.
Activity - 3: To study effect of intensity of light (by varying distance of the source) on an LDR. 107
Activity - 4. To observe refraction and lateral deviation of a beam of light incident obliquely on a glass slab. 108
Activity - 5. To observe diffraction of light due to a thin slit. 110
Activity - 6. To study the nature and size of the image formed by a concave mirror, on a screen 111
by using a candle and a screen (for different distances of the candle from the mirror).
Activity - 7. To study the nature and size of the image formed by a convex lens, on a screen by 113
using a candle and a screen (for different distances of the candle from the lens).
Activity - 8. To obtain a lens combination with the specified focal length by using two lenses from 115
the given set of lenses.

INVESTIGATORY PROJECTS

Project - 1: To study various factors on which the internal resistance/E.M.F. of a cell depends. 118
Project - 2: To study the variations in current flowing in a circuit containing an LDR because of a variation in 121
(a) the power of the incandescent lamp used to ‘illuminate’ the LDR (keeping all the lamps at
a fixed distance).
(b) the distance of an incandescent lamp (of fixed power) used to 'illuminate' the LDR.
Project - 3: To find the refractive indices of (a) water (b) oil (transparent) using a plane mirror, an equiconvex 123
lens (made from a glass of known refractive index) and an adjustable object needle.

Project - 4: To investigate the relation between the ratio of (i) output and input voltage and (ii) number of 128
turns in the secondary coil and primary coil of a self-designed transformer.
Project - 5: To investigate the dependence of the angle of deviation on the angle of incidence using a 130
hollow prism filled one by one, with different transparent fluids.
Project - 6: To estimate the charge induced on each one of the two identical Styrofoam (or pith) balls 133
suspended in a vertical plane by making use of Coulomb's law.
Project - 7: To study the factor on which the self-inductance of a coil depends by observing the effect of this coil, 134
when put in series with a resistor/(bulb) in a circuit fed up by an A.C. source of adjustable frequency.
Project - 8: To study the Earth’s magnetic field using a compass needle-bar magnet by plotting magnetic 137
field lines and tangent galvanometer.

Appendix - I: Useful Conversion Factors 141

Appendix - II: Dielectric Constants of Some Common Materials (at 20°C) 142
Appendix - III: Fundamental Physical Constants 143

Appendix - IV: Some Useful Tables 144