The separation between an electron and a proton in a hydrogen atom is \( 0.83 \text{ \AA} \). Find the electric force of attraction between them.

If the speed of rotation of the armature of a generator is increased, how would it effect (i) The maximum emf produced (ii) The frequency of the emf?

A Television transmitting antenna is 84m tall. How much service area can it cover, if the receiving antenna is at the ground level?

When we draw the variation of the potential energy of a pair of nucleons with their separations, then

The average drift speed of conduction electrons in a copper wire of cross-sectional area \( 1.0 \times 10^{-7} \text{ m}^2 \) carrying a current of 1.5 A. (Assume the density of conduction electrons to be \( 9 \times 10^{28} /\text{m}^3 \))

In an a. c. series LCR circuit, the applied voltage is \(v=(100 \sqrt{2}) \sin (\omega t+\pi / 4)\) volt. Given that \(R=30 \Omega, X_L=50 \Omega\) and \(X_C=10 \Omega\). The value of power dissipated in the circuit is

In an AC circuit, the instantaneous values of emf and current are \( E = 100 \sin(314t) \) V and \( I = \sin(314t + \pi/3) \) A. The average power consumed in the circuit is:

Which of the following is true?

The area of the region bounded by \(y=-1, y=2, x=y^3\) and \(x=0\) is \(\frac{m}{n}\) sq. units, where \(\operatorname{gcd}(m, n)=1\), then \(m-n\) is equal to

In Young's double slit experiment, the light has a frequency \( 12 \times 10^{14} \text{ Hz} \) and the distance between the centres of adjacent fringes is 0.8 mm. If the screen is 1.6 m away, what is the distance between the slits? (Take speed of light \( c = 3 \times 10^8 \text{ m s}^{-1} \))

Read the passage carefully and answer the Questions
Alcohols and phenols are obtained when a hydrogen atom in aliphatic and aromatic hydrocarbons respectively, is replaced by \(OH\) group. These compounds find wide applications in industry as well as in our daily life. You may notice that ordinary spirit is used for polishing wooden furniture which is chiefly a compound containing hydroxyl group. An alcohol contains one or more hydroxyl \((OH)\) group(s) directly attached to carbon atom(s), of an aliphatic system \((CH_3OH)\) while a phenol contains \(OH\) group(s) directly attached to carbon atom(s) of an aromatic system \((C_6H_5OH)\). Alcohols are prepared by the hydration of alkenes, fermentation of glucose, and reduction of carbonyl compounds. Alcohols produce alkenes upon dehydration whereas alkenes on acid catalyzed hydration convert into alcohols.
Which of the following compounds lacks phenolic group?

In gel electrophoresis, the separated DNA fragment can be visualized -

Read the following paragraph carefully and answer the given questions.
In the year 1963 the two enzymes responsible for restricting the growth of bacteriophage in E. coli were isolated. The first restriction endonuclease - Hind II, whose functioning depended on a specific DNA nucleotide sequence was characterized five years later. It was found that Hind II always cut DNA molecules at a particular point by recognizing a specific sequence of six base pairs. This specific base sequence is known as the recognition sequence for Hind II. Besides Hind II, today we know more than 900 restriction enzymes that have been isolated from over 230 strains of bacteria, each of which recognize different recognition sequences.
Restriction enzymes are also known as