2. p − n junction is said to be forward biased, when ?

1. At absolute zero, Si acts as :

23. Which of the following phenomenon is not common to sound and light waves ?

1. Which one of the following phenomena is not explained by Huygens construction of wavefront?

26. Focal length of a convex lens of refractive index 1.5 is 2 cm. Focal length of the lens when immersed in a liquid of refractive index of 1.25 will be ?

Point charges +4q, −q and +4q are kept on the X-axis at points x = 0, x = a and x = 2a respectively. Then ___ ?