A current I flows through an infinitely long, straight copper walled pipe. Then:

The momentum of a photon associated with a radiation of frequency \(2 \times 10^{13} Hg\) is (Given: \(h=6.6 \times 10^{-34} J\) s and \(c=3 \times 10^8 m / s\) )

On adding a small amount of boron to a silicon crystal

A uniformly charged sphere of \( 80 \text{ } \mu\text{C} \) and radius 2 cm is placed in air.
The electric field intensity at a point 20 cm from the center of the sphere is:

Two antennas A and B have maximum line of sight range R = 45.5 km. If the height of antenna A is 32 m then the height of antenna B is : (Given radius of earth is = 6400 km)

The kinetic energy of an \(\alpha\)-particle incident on gold foil is reduced to half of its initial value. How does the distance of closest approach change?

The magnetic flux (Φ) through the area of cross-section of a current-carrying coil is proportional to the current (i) i.e., Φ = Li.
(A) L is self-inductance of the coil
(B) The self-inductance of the coil does not depend on its geometry
(C) self-inductance is the electromagnetic analogue of mass in mechanics
(D) The self-inductance of the coil depends on the permeability of the medium inside coil
Choose the correct answer from the options given below:

Read the passage carefully to answer the questions given below
Some strains of `Bacillus thuringiensis` produce proteins that kill certain insects such as lepidopterans (tobacco budworm, armyworm), coleopterans (beetles) and dipterans (flies, mosquitoes). In `Bacillus thuringiensis` the toxin is coded by a gene `crylAc` named cry. There are a number of them, for example, the proteins encoded by the genes `crylAc` and `cryllAb` control the cotton bollworms, that of `crylAb` controls corn borer. Using conventional methods of diagnosis (serum and urine analysis, etc.) early detection is not possible. Recombinant DNA technology, Polymerase Chain Reaction (PCR) and Enzyme Linked Immuno-sorbent Assay (ELISA) are some of the techniques that serve the purpose of early diagnosis. The first clinical gene therapy was given in 1990 to a 4-year old girl with adenosine deaminase (ADA) deficiency. This enzyme is crucial for the immune system to function. The disorder is caused due to the deletion of the gene for adenosine deaminase. `RNAi` takes place in all eukaryotic organisms as a method of cellular defense. This method involves silencing of a specific `mRNA` due to a complementary `dsRNA` molecule that binds to and prevents translation of the `mRNA`.
Which of the following Bt toxin gene controls the corn borer?

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.
Hind II is a restriction endonuclease because

The Net Primary Productivity (NPP) is:

A bar magnet of magnetic moment 3 J/T lies aligned with the directions of a uniform magnetic field of 0.2 T. The amount of work, required so as to align its magnetic moment opposite to the field direction is :

Which of the given example explains evolution by anthropogenic action?

A bulb of \( 100 \text{ W} \) glows for \( 6 \text{ hours} \) a day. The units of energy consumed in \( 7 \text{ days} \) would be :