A rod AB moves with uniform velocity v in a uniform magnetic field as shown in the figure. Identify the correct statement(s) among the following:

(A) Rod becomes electrically charged.
(B) End A becomes positively charged.
(C) End B becomes positively charged.
(D) Rod becomes hot due to joule's heating.
Choose the correct answer from the options given below:

Two identical short magnetic dipoles of magnetic moment \( 2 \text{ Am}^2 \) are placed with their axis mutually perpendicular and centers 2 m apart. The magnitude of the resultant magnetic field at the midpoint (O) between the dipoles is :

The displacements of four light waves are given below. If the amplitudes \( a_1 \) and \( a_2 \) are nearly equal, then the interference fringes may be observed due to superposition of:
(A) \( y = a_1 \sin \omega t \)
(B) \( y = a_2 \sin (\omega t + \phi) \)
(C) \( y = a_1 \sin 2\omega t \)
(D) \( y = a_2 \sin 3(\omega t + \phi) \)

A moving coil galvanometer has N number of turns in the coil with area A. It carries a current I and the magnetic field is B. The torque acting on the coil is :

Choose the correct formula for magnifying power of a simple microscope from the following

The circuits where transformers are used :

A beam of electron is used in Young's double slits experiment. The slit width is d . When velocity of electron is increased, then :

Read the following paragraph carefully and answer the given questions.
Certain types of leukocytes (WBC) of our body like polymorpho-nuclear leukocytes (PMNL-neutrophils) and monocytes and natural killer (type of lymphocytes) in the blood as well as macrophages in tissues can phagocytose and destroy microbes. For determining the cause of allergy, the patient is exposed to or injected with very small doses of possible allergens, and the reactions studied. The use of drugs like anti-histamine, adrenalin and steroids quickly reduce the symptoms of allergy. Heroin, commonly called smack is chemically diacetylmorphine which is a white, odourless, bitter crystalline compound. This is obtained by acetylation of morphine. Techniques like radiography (use of X-rays), CT (computed tomography) and MRI (magnetic resonance imaging) are very useful to detect cancers of the internal organs. Different species of Plasmodium (P. vivax, P. malaria and P. falciparum) are responsible for different types of malaria. Of these, malignant malaria caused by Plasmodium falciparum is the most serious one and can even be fatal.
Malignant malaria is caused by -

When an \( \alpha \)-particle of mass M moving with velocity v bombards a heavy nucleus of charge Ze, its distance of closest approach from the nucleus depends on M as

The initial idea of triplet nature of codon was proposed by:

The mean of the number of heads in the two tosses of a coin is

Which of the following is not an expression of Dalton's law of partial pressures?

The Photoelectric current from a photosensitive metal, above the threshold frequency, depends on the :