In the process of transcription,the sigma factor is important for:

The mid-point of a chord of the ellipse $x^2+4y^2-2x+20y=0$ is $(2, -4)$. The equation of the chord is

When a certain weight is suspended from a long uniform wire,its length increases by $1 \ cm$. If the same weight is suspended from another wire of the same material and length but having a diameter half of the first one,the increase in length will be ......... $cm$.

Which of the following statements is not correct?

$A$ sample of $0.1 \ g$ of water at $100^{\circ} C$ and normal pressure $(1.013 \times 10^5 \ N m^{-2})$ requires $54 \ cal$ of heat energy to convert to steam at $100^{\circ} C$. If the volume of the steam produced is $167.1 \ cc$,the change in internal energy of the sample is ....... $J$.

The half-life period of a first-order chemical reaction is $6.93 \, \text{min}$. The time required for the completion of $99 \%$ of the chemical reaction will be .......... $\text{min}$ $(\log \, 2 = 0.301)$.