Physics Test 16...

The area of each plate of a capacitor is S and it is completely filled with a dielectric as shown in figure. The dielectric constant and resistivity of the material of the slab inserted in the capacitor are K and ρ respectively. The emf of the ideal cell is V. The current flowing through dielectric slab immediately after the key is switched on is

A thin insulating rod of length ℓ carries a charge q distributed uniformly on it. The rod is pivoted at its mid point and is rotated at a frequency f about a fixed axis perpendicular to the rod and passing through the pivot. The magnetic moment of the rod system is

A particle of charge q and mass m starts moving from the origin under the action of an electric field The speed of the particle will become 2v₀ after a time

A cell of internal resistance 1Ω is connected across a resistor R. A voltmeter having variable resistance G is used to measure potential difference across the resistor. The plot of voltmeter reading V against G is shown. What is the value of external resistor R?

Consider the equation = linear momentum)

In the figure shown the cart of mass 6 m is initially at rest on a smooth horizontal surface. A particle of mass m is attached to the end of the light rigid rod which can rotate freely about end A in a vertical plane. If the rod is released from rest from the horizontal position as shown, find the velocity (v_rel) of the particle with respect to the cart when the rod is vertical.

The figure shows a square carrom board without any pockets. A coin is pushed from the corner, which is the origin, with a velocity  Assume gravity and friction to be absent. The coin collides with edges of the carrom board elastically. What is the velocity vector of coin after the 3rd collision?

Two point electric dipoles with dipole moments P₁ and P₂ are separated by a large distance ‘r’ with their dipole axes mutually perpendicular as shown. The electric force between the dipoles is 

Two small balls A and B of positive charge Q each and masses m and 2m respectively are connected by a non conducting light rigid rod of length L. This system is released in a uniform electric field of strength E as shown. Just after the release (assume no other force acts on the system).

The plane polarised light is passed through a polaroid. On viewing through the polaroid, we find that when the polaroid is given a complete rotation about an axis coinciding with the direction of the incident light, one of the following is observed,