19. In forward bias, the width of potential barrier in a p − n junction diode _____ ?

18. A depletion layer consists of ?

17. Which of the following when added acts as an impurity into silicon produced n-type semiconductor ?

16. In a junction diode, the holes are due to ?

5. Colours appear on a thin soap film and on soap bubbles due to the phenomenon of ?

53. The refractive index of the material of the prism is √ 3; then the angle of minimum deviation of the prism is ?

34. A plano-convex lens is made of material of refractive index 1.6. The radius of curvature of the curved surface is 60 cm. The focal length of the lens is ?

16. Wavelength of light of frequency 100 Hz ?

A parallel plate condenser with oil between the plates (dielectric constant of oil K = 2 ) has a capacitance C. If the oil is removed, then capacitance of the capacitor becomes ?

What is the effective capacitance between the points X and Y ?