An alpha-particle moves with a speed of \( (5 \times 10^5 \hat{i}) \text{ m s}^{-1} \).
It enters a region where there is a magnetic field of magnitude 4 T,
directed at an angle of 45° to the X-axis and lying in the XY-plane.
The magnitude of magnetic force on the alpha-particle is:

If the wavelength of light in an experiment on photoelectric effect is increased, then
(A) the photoelectric emissions will not take place
(B) the photoelectric emission may or may not take place
(C) the stopping potential will increase.
(D) the stopping potential will decrease
Choose the correct answer from the options given below:

Two charges of equal magnitude and at distance r exert a force F on each other. If each charge is doubled and the distance between them is halved, then the new force acting on each charge will be

The nuclear force is a short range force, this can be explained by fact that the binding energy per nucleon versus mass number curve:

In the nuclear decay given below, the particles emitted in the sequence are:

Magnetic field at large distances on the axis of a current carrying circular loop depends on distance from the centre as

A current of \(1.0\) mA is flowing through a potentiometer wire of length 4 m and of resistance \( 40 \, \Omega \). The potential gradient of the potentiometer wire will be :

Which of the following statements are correct?
(A) In an ac circuit containing only resistance, power consumption is \( I^2 R \).
(B) In an LCR circuit, there is resonance at zero phase difference between \( X_C \) and \( X_L \) and the power consumption is \( I(\omega X_C + \omega X_L)^{1/2} \).
(C) In an LCR circuit, at resonance, impedance is minimum.
(D) In an LCR circuit, there is resonance at zero phase difference between \( X_C \) and \( X_L \) and the power consumption is zero.
Choose the correct answer from the options given below:

Sudhir had Rs 45,000. He lent a part of it at 4% p.a. and the remaining at 10% p.a. simple interest. He earned a total profit at 8% p.a. on the money lent, what sum did he lend at 10% p.a ?

Read the passage carefully and answer the questions given along
Our immune system plays the major role in preventing diseases when we are exposed to disease-causing agents. Immunity is of two types: (i) Innate immunity and (ii) Acquired immunity. The human immune system consists of lymphoid organs, tissues, cells and soluble molecules like antibodies. The immune system also plays an important role in allergic reactions, auto-immune diseases and organ transplantation. The primary lymphoid organs are bone marrow and thymus. The secondary lymphoid organs are spleen, lymph nodes, tonsils, Peyer's patches of small intestine and appendix. There is lymphoid tissue also located within the lining of the major tracts (respiratory, digestive and urogenital tracts) called mucosa associated lymphoid tissue (MALT). It is important to note that HIV/AIDS is not spread by mere touch or physical contact; it spreads only through body fluids. AIDS has no cure, prevention is the best option. Adolescence is accompanied by several biological and behavioural changes and surveys and statistics show that use of drugs and alcohol has been on the rise especially among the youth. Factors associated with drug and alcohol abuse among adolescents are a child's natural curiosity, stress, the perception among youth that it is 'cool' or progressive to smoke, media exposure and an unstable or unsupportive family structures and peer pressure. It is best to identify the situations that may push an adolescent towards use of drugs or alcohol, and to take remedial measures well in time.
Find the incorrect statement about human health and disease.

When aniline is reacted with benzoyl chloride, the correct product is

Bioactive molecule, cyclosporin A, that is used as an immunosuppressive agent in organ-transplant patients, is produced by the fungus -

A piece of silver and another of silicon are cooled from 15 ℃ to 3 ℃. What will be the effect on resistance of each?