The energy of electron in the first excited state of Hydrogen atom is -3.4 eV. The potential energy of this electron is :

The radius of the first orbit in Bohr's hydrogen atom is 0.53\(\text{\AA}\). The radius of fourth orbit of this atom will be:

Why the Fusion reaction takes place at high temperature among the nuclei, though these experience repulsion between them:

Three particles, each having a charge of \( 10 \, \mu\text{C} \), are placed at the vertices of an equilateral triangle of 10 mm. Find the work done by a person in pulling them apart to infinite separation.

A very long solenoid has 800 turns per unit length. A current of 1.6 A flows through it. Then the magnetic induction in the middle of the solenoid on its axis is approximately :
(1) \( 16 \times 10^{-4} \text{ T} \)
(2) \( 8 \times 10^{-4} \text{ T} \)
(3) \( 32 \times 10^{-4} \text{ T} \)
(4) \( 4 \times 10^{-4} \text{ T} \)

Which of the following is the wrong statement? Coulomb's law describes the electric force that

Two capacitors of capacitance of \( 6 \, \mu\text{F} \) and \( 12 \, \mu\text{F} \) are connected in series with a battery. The voltage across \( 6 \, \mu\text{F} \) capacitor is 2 V. The total voltage across the combination is

MONOHYBRID CROSS
The inheritance of flower color in the dog flower (Snapdragon or Antirrhinum sp.) can be understood by crossbreeding between true-breeding red-flowered (RR) and true-breeding white-flowered plants (rr). When they were crossed, F₁ (Rr) was pink. When F₁ was self-pollinated, the F₂ results were Red, Pink and White. Here the genotype ratios were exactly as expected, but the phenotype ratios have been changed. What happened was that R was not completely dominant over r and this made it possible to distinguish Rr as pink from RR (Red) and rr (White).
What will be the genotypic ratio in F₂ generation when F₁ (Rr) was self-pollinated?

We use microbes and microbially derived products almost every day. Bacteria called lactic acid bacteria (LAB) grow in milk to convert it into curd. The dough, which is used to make bread, is fermented by yeast called Saccharomyces cerevisiae. Microbes are used to produce industrial products like lactic acid, acetic acid and alcohol, which are used in a variety of processes in the industry. However, certain bacteria, which grow anaerobically on cellulosic material, produce large amount of methane along with CO2 and H2. These bacteria are collectively called methanogens, and one such common bacterium is Methanobacterium. These bacteria are commonly found in the anaerobic sludge during sewage treatment. Microbes are also used for commercial and industrial production of certain chemicals like organic acids, alcohols and enzymes.
Examples of acid producers are Aspergillus niger (a fungus) of citric acid. You are familiar with the commonly used antibiotic Penicillin. Do you know that Penicillin was the first antibiotic to be discovered, and it was a chance discovery? Statins produced by the yeast Monascus purpureus have been commercialised as blood-cholesterol lowering agents. It acts by competitively inhibiting the enzyme responsible for synthesis of cholesterol.
Which one of the following statements is not true with respect to microbes?

Match List-I with List-II:

List-I (Physical quantity)	List-II (Formula)
(A) Width of a central maximum	(I) 2\(\lambda\)/a
(B) Fringe width	(II) a\(^2\)/\(\lambda\)
(C) Fresnel's distance	(III) 2D\(\lambda\)/a
(D) Angular speed of central maximum	(IV) D\(\lambda\)/d

Choose the correct answer from the options given below:

Why does colour of \(KMnO_4\) disappear when oxalic acid is added to its solution in acidic medium?

The value of \(3^{18}(\bmod 4)\) is equal to

The hormone releasing IUDs function by-