Q. 1. Define ‘Electrochemical Equivalent’ of a substance.
Q. 2. The equivalent capacitance of the combination
between A and B in the given figure is 15 μF. Calculate the capacitance
of capacitor C.
Q. 3. Name the electromagnetic radiations used for
studying crystal structures of solids.
Q. 4. In a series LCR circuit, the voltages across an
inductor, capacitor and resistor are 40 V, 20 V and 20 V respectively. What
is the total voltage operative across the combination?
Q. 5. How does the width of depletion region in a p-n
junction change when it is reverse biased?
Q. 6. The vertical component of earths’ magnetic field
at a place is 1/√3 times its horizontal component. What is the value
of angle of dip at this place?
Q. 7. Write the truth table for the combination of gates
shown in the diagram.
Q. 8. Write the ratio of brightness of two stars having
magnitudes of - 5 and 0 respectively.
Q. 9. Two point electric charges A and B of 1.5 μC
and 2.5 μC respectively are kept 30 cm apart in air. Calculate the
electric potential at a point C which is 10 cm from the mid point of
straight line AB and is on a plane normal to AB and is passing through the
mid point of this line.
Q. 10. Calculate the equivalent resistance of the
resistance network between the points A and B as shown in the figure when
switch S is closed.
Q. 11. State Faraday’s laws of electrolysis.
Q. 12. Write two essential conditions for total internal
reflection to take place in a transparent medium. Give two examples of this
phenomenon in daily life situations.
Q. 13. Work functions of three elements A, B, C are as
given below
A 5.0 eV B 3.8 eV C2.8eV
A radiation of wavelength 4125 A is made to be incident on each of these
elements. By appropriate calculations show in which case photoelectrons will
not be emitted.
Q. 14. Glass has a refractive index of 1.5. A convex
lens made of thin glass has a focal length of 20 cm in air. It is immersed
in water whose refractive index is 4/3. Calculate the apparent changed focal
length of the fens.
Q. 15. Derive the mathematical expression for surface
temperature of sun in terms of solar constant.
Q. 16. How can a galvanometer of resistance G be
converted into a voltmeter to read a maximum potential difference of ‘V
volts. Support your with related mathematical expression.
Q. 17. When a capacitor is added in series to an L-R
series circuit, the alternating current flowing in the circuit increases.
Give reasons.
Q. 18. Define the term ‘electrical resistivity’ of a
material. How is it related to its ‘electrical conductivity’? Of the
factors length, area of cross section, nature of material and temperature,
which ones control the resistivity value of a conductor?
Q. 19. You are given three lenses having powers P and
apertures A as follows
P1 = 6D, A1 = 3 cm
P2 = 3d, A2 = 15 cm
P3 = 12D, A3 = 1.5 cm
Which two of these lenses will you select to construct (;) a telescope and
(if) a microscope? State the basis for your in each case.
Q. 20. Distinguish between conductors, insulators and
semi¬conductors on the basis of energy band diagrams.
Q. 21. Sketch the wavefront corresponding to parallel
rays. Verify SnelPs law of refraction using Huygen’s wave theory.
Q. 22. A 10 m long wire AB of uniform area of
cross-section and 20 Ω resistance is used as a potentiometer wire.
This wire is connected in series with a battery of 5 V and a resistance of
480 Ω. An unknown emf E is balanced at 600 cm of the wire as shown in
the figure.
Calculate (i) the potential gradient for the potentiometer wire, (if) the
value of unknown emf E.
Q. 23. State the principle of a vibration magnetometer.
Explain how it can be used to compare the magnetic moments of two bar
magnets of same size and same mass?
Q. 24. Write the expression of Biot-Savart law for the
magnetic field due to a small current carrying element. Using this
expression, calculate the magnetic field at the centre of a circular coil of
radius r and number of turns n.
Q. 25. State the conditions for obtaining sustained
interference of light from different sources. The ratio of intensities of
maxima and minima in an interference pattern is found to be 25 9. Calculate
the ratio of light intensities of the sources producing this pattern-
Q. 26. Explain, with the help of a circuit diagram, the
use of a p-n diode as a full wave rectifier. Draw the input and output
voltage waveforms.
Q. 27. Define the term ‘Binding Energy (BE)’ of a
nucleus. Compute B.E/nucleon for 26Fe56. Given
mass of proton = 1.007825 u
mass of neutron = 1.008665 u
mass of 26Fe56 nucleus = 55.934939 u and 1 u = 931.5
MeV.
Q. 28. State Gauss’s theorem in electrostatics and
express it mathematically. Using it, derive an expression for electric field
at a point near a thin infinite plane sheet of electric charge. How does
this electric field change for a uniformly thick sheet of charge?
Q. 29. Explain, with the help of a labelled diagram, the
principle, construction and working of an a.c. generator.
Or
Explain, with the help of a labelled diagram, the principle, construction
and working of a step-up transformer.
Q. 30. State the postulates of Bohr’s atomic model.
Apply these postulates to drive a mathematical expression for energy of an
electron in an atomic orbit.