If the flux of the electric field through a closed surface is zero.
(A) The electric field must be zero everywhere on the surface.
(B) The electric field may be zero everywhere on the surface.
(C) The charge inside the surface must be zero.
(D) The charge in the vicinity of its surface must be zero.
(E) The charge inside the surface may be zero.
Choose the correct answer from the options given below :

The refractive index of the material of an equilateral prism is \(\sqrt{2}\). The angle of minimum deviation of that prism is :

An AC (220 V, 50 Hz) circuit has a resistance of 3 \(\Omega\) and an impedance of 5 \(\Omega\) . The power factor of the circuit will be :

A glass prism of angle 60° has an angle of minimum deviation of 30° for a given colour of light. The refractive index of glass for that colour of light is :

A proton moves with a velocity equal to \( \left( \frac{1}{20} \right)^{\text{th}} \) of velocity of light.
The associated de-Broglie wavelength is:

The critical angle of incidence \( i_c \) for a ray incident from a denser to a rarer medium, is that angle for which

A capacitor is charged through a potential difference of 200 V, when 0.1 C charge is stored in it. When it is discharged, the energy it will release would be :

Name the reaction when a mixture of acetaldehyde and propanal is treated with aqueous alkali solution.

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.
Some strains of Bacillus thuringiensis produce proteins that do not kill certain arthropods, such as:

A region has a uniform magnetic field in it. A proton enters the region with a velocity, making an angle of \( 45^\circ \) with the direction of the magnetic field. In this region the proton will move in :

The value of a depreciable asset at the end of its useful life is called __________ .

According to the electrochemical series, which of the following statements is incorrect?

Which of the following is not made by fermentation?