Rutherford’s scattering experiment is related to the size of the

If the length of a stretched string is shortened by $40 \%$ and the tension is increased by $44 \%$,then the ratio of the final and initial fundamental frequencies is :

Carbon,silicon,and germanium have four valence electrons each. These are characterized by valence and conduction bands separated by energy band gaps equal to $(E_{g})_{C}$,$(E_{g})_{Si}$,and $(E_{g})_{Ge}$ respectively. Which of the following statements is true?

Statement $P$: Every living organism exhibits unique characteristics such as reproduction,growth,development,adaptation,and death.
Statement $Q$: Energy transformation is essential for every living organism.

The kinetic energy $K$ of a particle moving along the $x$-axis varies with its position $x$ as shown in the figure. The magnitude of the force acting on the particle at $x = 9 \, m$ is ............ $N$.

The magnetic field at the centre of a circular current-carrying conductor of radius $r$ is $B_c$. The magnetic field on its axis at a distance $r$ from the centre is $B_a$. The value of $B_c : B_a$ will be: