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SECTION A (8 x 1)

Question 1
A IC charge is placed at a point O. What is the work done in moving a 2C charge once along a circle of radius 10cm and centre O?

Question 2
What is the absolute permitivity of a medium whose dielectric constant is one?

Question 3
Draw an equipotential surface for
a) uniform electric field
b) non uniform electric field.

Question 4
If the temperature of the cold junction in a thermocouple is decreased, what will be its effect on the neutral temperature and the temperature of inversion?

Question 5
An electron travelling West to East enters a chamber having a uniform electrostatic field in a North to South direction. Specify the direction in which a uniform magnetic field should be set up to prevent the electron from deflecting from its straight line path.

Question 6
A charged particle is moving in a uniform magnetic field with varying speeds. Out of the following physical quantities which physical quantity remains unaltered.
a) kinetic energy
b) linear momentum
c) radius
d) angular frequency

Question 7
Does a Conductor become charged when a current is flowing through it?

Question 8
A wire of receptivity 49 x 10-6Wcm. is stretched to three times its original length. What will be the new receptivity of the wire?

SECTION B (10 X 2)

Question 9
State Biot Savart's Law
What is the magnetic field induction at the point 0
due to a current flowing in an infinite shaped
wire as shown in the figure?

Question 10
The current 'i', (A) flowing through a wire depends on time 't', (sec) as i = 10 + 4t. What is the charge crossing through a section of the wire in 10 sec?

Question 11
Draw a neat well labelled diagram of a Lechlancle cell.

Question 12
The plots for the current i (A) flowing through a metallic resistor versus the potential drop V (volts) across the resistor at two different temperatures T1 & T2 is shown in the figure. Which of the two temperatures T1 & T2 is higher and explain why?

Question 13
Calculate the electric force experienced by an electron drifting through a copper wire of cross sectional area 5 mm2 carrying a current of 1A. The receptivity of copper is 1.5 x 10-6Wcm.

Question 14
State two reasons why electrolytes have lower electrical conductivity than metallic conductors in general.

Question 15
Derive an expression for the electric potential at a point along the axial line of an electric dipole.


Question 16
State Gauss's Law.
A charge of 42mc is located at the centre of a cube & a charge of 36mc is located outside the cube. What is the electric flux linked with any one face of the cube?

Question 17
A proton and an alpha particle accelerated through the same potential difference enter normally into a magnetic field of strength B. Determine the ratio of x to rp where rp & r are their respective radii of their circular paths.

Question 18
Two bulbs of rating 100w-220V and 40w-220V are connected in series across a 220 V supply. Justify with necessary calculations which bulb will glow brighter.

SECTION C (9 X 3)

Question 19
With the help of a neat well labelled circuit diagram describe the method to determine the internal resistance of a primary cell.

Question 20
The voltmeter connected across the 600W resistor has a resistance of 600W. Determine the potential drop read by the voltmeter.

Question 21
In a triangle ABC, the sides AB, BC and CA are 5cm, 4cm and 3cm respectively. If the charges 12pc and 16pc are placed at A and B respectively, determine the electric field intensity at C. What will be the force experienced by HOC charge placed at C.

Question 22
An isolated hollow conducting spherical shell of radius 'R' carries a charge 'Q'. Plot the variation of the electrostatic field intensity, the corresponding potential and the electric flux with distance r, as measured from the centre of the sphere.

Question 23
a) On a neat well labelled diagram depict the elements of the earth's magnetic field.
b) It is observed that the neutral points lie along the equatorial line of a magnet placed on the Table. What is the orientation of the magnet with respect to the earth's magnetic field?

Question 24
A thin magnetic needle vibrates, in a vibration magnetometer, in the horizontal plane with a period of 16 seconds. The needle is cut into two halves by a plane normal to the magnetic axis of the needle. Determine the period of vibration of each half needle.

Question 25
In the circuit, the charge on the capacitor c2 is 2mC and the charge on the capacitor c3 is 3mC. If the capacitance of c2 is 2mF. Determine
a) the potential drop across C1
b) the equivalent capacitance of the circuit c) the energy dissipated in the curcuit.

Question 26
Derive an expression for the torque on a rectangular coil o area 'A', carrying a current 'i' and placed in a uniform magnetic field B, such that the normal to the plane of the coil makes an angle q with the direction of B. If the coil is left on its own, how does it tend to orient itself relative to the magnetic field.

Question 27
Write the expression for the force between two parallel straight conducting wires carrying a current 'i' & separated by a distance by a distance 'a' in vacuum,
b) Two parallel wires carrying current in the same direction attract each other, while two beams of electrons travelling in the same direction repel each other. Explain.

SECTION D (3 X 5)

Question 28
a) Plot the variation of thermo e.m.f E(mV) with the temperature of the hot junction, temperature of the cold junction of the thermocouple being maintained at 00C.
b) The following plot represents the variation of Thermoelectric power S(mV0C-1)

with the temperature of the hot junction qoC. for a Silver-Iron
thermocouple, the temperature of the cold junction is maintained at O0C. Determine
a) the thermoelectric coefficients
b) the neutral temperature and temperature of inversion.
c) If the cold junction was maintained at 400C what be the neutral temperature and temperature of inversion.

Question 29
a) State the principle of a tangent galvanometer. Name the two fields which influence the deflection of the magnetic needle in a tangent galvanometer
b) How will the reduction factor of a tangent galvanometer be affected when the
(i) number of turns of its coil is doubled?
(ii) the radius of the coil is increased?
(iii) the angle of dip at the location of the experiment increases?

Question 30

A parallel plate air cored capacitor is connected to a battery. The battery is disconnected and a dielectric slab is inserted between the plates. Describe qualitatively what happens to the charge, capacitance & energy stored in the capacitor? What would be the charge, capacitance & energy stored in the capacitor if the battery had not been disconnected & the dielectric inserted?
OR
a) Derive an expression for the total capacitance when three capacitors are connected in a) series b) parallel.

b) A2mF capacitor charged to a potential difference of 100V and a 8mF capacitor charged to a potential difference of 50V are connected together in parallel. Find the loss in energy due to the connection.

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