Consider two point charges q₁ and q₂ at rest as shown in the figure.

They are separated by a distance of 1m. Calculate the force experienced by the two charges for the following cases:
(a) q₁ = +2μC and q₂ = +3μC
(b) q₁ = +2μC and q₂ = -3μC
(c) q₁= +2μC and q₂ = -3μC kept in water (ε_r = 80)

Consider four equal charges q₁, q₂, q₃ and q₄ = q = +1 μC located at four different points on a circle of radius 1m, as shown in the figure. Calculate the total force acting on the charge q₁ due to all the other charges.

(a) Calculate the electric potential at points P and Q as shown in the figure below.
(b) Suppose the charge + 9μC is replaced by - 9 μC find the electrostatic potentials at points P and Q.

(c) Calculate the work done to bring a test charge +2 μC from infinity to the point Q. Assume the charge +9 μC is held fixed at origin and +2 μC is brought from infinity to P.

Define potential difference and derive.

Consider a rectangular block of metal of height A, width B and length C as shown in the figure.

If a potential difference of V is applied between the two faces A and B of the block (figure (a)), the current I_AB is observed. Find the current that flows if the same potential difference V is applied between the two faces B and C of the block (figure (b)). Give your answers in terms of I_AB.

Calculate the magnetic field at a point on the axial line of a bar magnet.

What is the value of the magnetic field at point O due to a current flowing in the wires?

The magnetic flux passes perpendicular to the plane of the circuit and is directed into the paper. If the magnetic flux varies with respect to time as per the following relation \(\Phi_B\) = (2t³ + 3t² + 8t + 5)mWb, what is the magnitude of the induced emf in the loop when t = 3 s? Find out the direction of current through the circuit.

What is impedance? When does LCR circuit have minimum impedance?

Obtain the equation for lateral displacement of light passing through a glass slab.

A thin rod of length f /3 is placed along the optical axis of a concave mirror of focal length f such that one end of image which is real and elongated just touches the respective end of the rod. Calculate the longitudinal magnification.

Determine the focal length of the lens made up of a material of refractive index 1.52 as shown in the diagram. (Points C₁ and C₂ are the centers of curvature of the first and second surfaces respectively.)

If the focal length is 150 cm for a lens, what is the power of the lens?

(i) Draw a graph showing variation of photoelectric current (I) with anode potential (V) for different intensities of incident radiation. Name the characteristic of the incident radiation that is kept constant in this experiment.
(ii) If the potential difference used to accelerate electrons is doubled, by what factor does the de-Broglie wavelength associated with the electrons change?

Discuss the Millikan’s oil drop experiment to determine the charge of an electron.

In a transistor connected in the common base configuration, \(\alpha\) = 0 95, I_E = 1 mA. Calculate the values of I_C and I_B.

Give the Schematic representation of valence band, conduction band, and forbidden energy gap and draw energy band structure of
(a) Insulators
(b) Semiconductors
(c) Metals?

A transmitting antenna has a height of 40 m and the height of the receiving antenna is 30 m. What is the maximum distance between them for line-of-sight communication? The radius of the earth is 6.4 × 10⁶ m.

What are the advantages and Limitations of FM?

What is robotics?