Which of the following is the pair of biofertilizers?

$50 \Omega$ and $100 \Omega$ resistors are connected in series. This combination is connected to a battery of $2.4 \text{ V}$. When a voltmeter of $100 \Omega$ resistance is connected across the $100 \Omega$ resistor,the reading of the voltmeter will be .......... $\text{V}$.

Which of the following substances combines with hemoglobin in the blood to form carboxyhemoglobin?

The first operation involved in a Carnot cycle is

Define the octet rule. Write its significance and limitations.

According to the widely accepted "fluid mosaic model", cell membranes are semi-fluid, where lipids and integral proteins can diffuse randomly. In recent years, this model has been modified in several respects. In this regard, which of the following statements is incorrect?