From the combination of resistors with resistances values $R_1=R_2=R_3=5 \Omega$ and $R_4=10 \Omega$, which of the following combination is the best circuit to get an equivalent resistance of $6 \Omega$ ?

Consider a n-type semiconductor in which $\mathrm{n}_{\mathrm{e}}$ and $\mathrm{n}_{\mathrm{h}}$ are number of electrons and holes, respectively.

(A) Holes are minority carriers

(B) The dopant is a pentavalent atom

(C) $\mathrm{n}_{\mathrm{e}} \mathrm{n}_{\mathrm{h}} \neq \mathrm{n}_i^2$

(where $\mathrm{n}_i$ is number of electrons or holes in semiconductor when it is intrinsic form)

(D) $\mathrm{n}_{\mathrm{e}} \mathrm{n}_{\mathrm{h}} \geqslant \mathrm{n}_i^2$

(E) The holes are not generated due to the donors

Choose the correct answer from the options given below :

Given below are two statements :

Statement (I) : The dimensions of Planck's constant and angular momentum are same.

Statement (II) : In Bohr's model electron revolve around the nucleus only in those orbits for which angular momentum is integral multiple of Planck's constant.

In the light of the above statements, choose the most appropriate answer from the options given below :

A solid sphere with uniform density and radius $R$ is rotating initially with constant angular velocity $\left(\omega_1\right)$ about its diameter. After some time during the rotation its starts loosing mass at a uniform rate, with no change in its shape. The angular velocity of the sphere when its radius become $\mathrm{R} / 2$ is $x \omega_1$. The value of $x$ is _________.