A thin infinite sheet charge and an infinite line charge of respective charge densities +σ and +λ are placed parallel at a distance of 5 m from each other. Points 'P' and 'Q' are at perpendicular distances of π3 m and π4 m from the line charge towards the sheet charge, respectively. Let E P and E Q be the magnitudes of the resultant electric field intensities at points 'P' and 'Q', respectively. If E Q E P = a4 for 2∣σ∣=∣λ∣, then the value of a is:

Which of the following statements are correct regarding electrostatic properties of conductors? A. Inside a conductor, the electrostatic field is zero. B. Electric field at the surface of a charged conductor does not depend on its surface charge density. C. The interior of a charged conductor can have no excess charge in static conditions. D. At the surface of a charged conductor, the electrostatic field must be normal to the surface at every point. E. The electrostatic potential is zero everywhere inside a charged conductor. Choose the correct answer:

What type of electric charge is acquired by a glass rod when it is rubbed with a silk cloth?