Name the particle 'X' emitted in the nuclear reaction given below -
\( {}_{11}^{22}Na \rightarrow {}_{10}^{22}Ne + \nu + X \)

The mobility of charge carriers increases with

Two resistances are connected in two gaps of a metre bridge. The balance point is 20 cm from the zero end. A resistance of \(3 \Omega\) is connected in series with the smaller resistance, then the null point shifts to 40 cm. The value of the smaller resistance is:

What will be the ratio of radii of two nuclei having their mass numbers in the ratio of 64:125?

When a positive charge (+ q) is brought near one face of a metal cube, the

The ratio of intensities of maxima to minima in the Young's double slits experiment is 9:4. The ratio of the widths of the two slits is:

An electric motor is driven by d.c. supply of emf \( V_0 \) and internal resistance r. The current when output power is maximum will be

Read the following paragraph and answer the given questions.
Bio-fertilisers are organisms that enrich the nutrient quality of the soil like cyanobacteria, while there are organisms that help to control plant diseases and pests. The very familiar beetle, the ladybird and dragonflies are useful to get rid of aphids and mosquitoes, respectively. An example of microbial biocontrol agents that can be introduced to control butterfly caterpillars is certain bacteria, which are available in sachets in the form of dry spores. These spores are mixed with water and sprayed onto vulnerable plants. Trichoderma species that are very common in the root ecosystem, are very effective biocontrol agents of several plant pathogens.Baculoviruses attack insects and other arthropods. Usage of these viruses is desirable when an ecological sensitive area is being treated..
A farmer wants to get rid of aphids, but does not want to use insecticide, Choose the best option for him?

An object is placed at a distance of 10 cm from a concave mirror of focal length 15 cm. The magnification of the image is

Identify the correct statement in the context of Rutherford scattering of \( \alpha \)-particles by a target nucleus:

Read the following passage carefully and answer the given questions.
Cancerous cells just continue to divide giving rise to masses of cells called tumors. Benign tumors normally remain confined to their original location and do not spread to other parts of the body and cause little damage. The malignant tumors, on the other hand are a mass of proliferating cells called neoplastic or tumor cells. Transformation of normal cells into cancerous neoplastic cells may be induced by physical, chemical or biological agents. Ionising radiations like X-rays and gamma rays and non-ionizing radiations like UV cause cancer. Cancer-causing viruses are called oncogenic viruses which have viral oncogenes. The substances to which an immune response is produced are called allergens. The antibodies produced to these are of IgE type. Common examples of allergens are mites in dust, pollens, animal dander, etc. The primary lymphoid organs are bone marrow and thymus. The secondary lymphoid organs provide the sites for interaction of lymphocytes with the antigen, which then proliferate to become effector cells.
Which one of the following antibodies are produced in response to the allergens?

Identify the important features of the semiconductor devices from the following
1. Semiconductor devices require cathode heating for the production of charge carriers.
2. They have long life and high reliability.
3. They are small in size and consume low power.
4. They operate at high voltage.
Choose the correct answer from the options given below:

Sparrow comes under which of the following categories: