A wheel with 10 metallic spokes each of length 1.0 m long is rotated with a speed of 240 rev/min in a plane normal to magnetic field of 0.4 G at the place, the induced emf between the axle and the rim of the wheel is: Given that 1 G = \(10^{-4}\) T.

In this diagram, three infinite plane sheets of charges are shown with surface charge densities \(+\sigma, +\sigma, -\sigma\). The value of electric field at points A and B are

A circular coil of area \( 300 \text{ cm}^2 \) and 25 turns rotates about its vertical diameter with an angular speed of \( 40 \text{ rad s}^{-1} \) in a uniform horizontal magnetic field of magnitude 0.05 T. The maximum voltage induced in the coil is

The speed of electromagnetic waves in a material medium is given by (symbols have their usual meanings):

The coil of a moving coil galvanometer is wound over a metallic frame

The wavelength of photon emitted by a hydrogen atom when an electron makes a transition from n = 2 to n = 1 state is. (Take the value of the Rydberg constant, \(R = 1.0973 \times 10^7 \text{ m}^{-1}\))

Each resistor shown in figure has a resistance of \( 20 \, \Omega \) and the battery has an emf of 12 V. The current supplied by the battery is

If \(\left[\begin{array}{ccc}x-2 & 3 & -2 \\ y & 0 & -4 \\ 2 & z & 0\end{array}\right]\) is a skew symmetric matrix, then the value of \(x+y+z\) is

The equation of the tangent to the curve \(y=\frac{x-5}{(x-3)(x+2)}\) at the point where it cuts the \(x\)-axis is :

For \(x \in\left(0, \frac{\pi}{2}\right), \int \frac{\sin x+\cos x}{\sqrt{\sin 2 x}} d x\) is equal to

Read the following features of the Photoelectric effect.
(A) The maximum kinetic energy of the photoelectrons varies linearly with the frequency of incident radiation
(B) The maximum kinetic energy of the photoelectrons is dependent on its intensity.
(C) For a frequency of incident radiation, lower than the cut-off frequency, photoelectric emission is possible even if the intensity is not large.
(D) Ultraviolet light can eject photoelectrons from copper even if visible light does not eject
Choose the correct answer from the options given below:

Read the following passage carefully and answer the given questions.
Some strains of Bacillus thuringiensis produce proteins that kill certain insects such as lepidopterans (tobacco budworm, armyworm), coleopterans (beetles) and dipterans (flies, mosquitoes). B. thuringiensis forms protein crystals during a particular phase of their growth. Transgenic animals that produce useful biological products can be created by the introduction of the portion of DNA (or genes) which codes for a particular product such as human protein (a-1-antitrypsin) used to treat emphysema. In 1997, the first transgenic cow, Rosie, produced human protein-enriched milk (2.4 grams per litre). The milk contained the human alpha-lactalbumin and was nutritionally a more balanced product for human babies than natural cow-milk. A nematode Meloidegyne incognitia infects the roots of tobacco plants and causes a great reduction in yield. A novel strategy was adopted to prevent this infestation which was based on the process of RNA interference (RNAi). This method involves silencing of a specific mRNA due to a complementary dsRNA molecule that binds to and prevents translation of the mRNA (silencing). Biopiracy is the term used to refer to the use of bio-resources by multinational companies and other organisations without proper authorisation from the countries and people concerned without compensatory payment. ELISA is based on the principle of antigen-antibody interaction. Infection by pathogen can be detected by the presence of antigens (proteins, glycoproteins, etc.) or by detecting the antibodies synthesised against the pathogen.
ELISA is based on the principle of:

Two waves of amplitudes 3 m and 2 m, respectively superimpose at a point in the same phase. The resultant amplitude would be