The magnetic field produced at the centre of circular loop of diameter 4 cm is \( 6.28 \times 10^{-5} \text{ T} \). The current required to flow in the loop is : (\( \mu_0 = 4\pi \times 10^{-7} \text{ N A}^{-2} \))

For transistor action, which of the following statements are correct
A. Both the emitter junction as well as the collector junction are forward biased.
B. The base region must be very thin and lightly dopped.
C. Base, emitter and collector should have same doping concentration.
D. The emitter junction is forward and collector junction is reverse bias.
Choose the correct answer from the options given below:

Magnetic moment of a thin bar magnet is 'M'. If it is bent into a semicircular form, its new magnetic moment will be :

A coil and a bulb are connected in series with a dc source. When a soft iron piece is inserted in the coil. Then,

An angular magnification of 30 X is desired using an objective lens of focal length 1.25 cm and an eyepiece of focal length 5 cm. What should be the separation between objective and eyepiece when the final image is formed at the near point ?

Two parallel large thin metal sheets have equal charge densities of \( 5.31 \times 10^{-11} \text{ C/m}^2 \) of opposite signs. If the permittivity of free space is \( \epsilon_0 = 8.85 \times 10^{-12} \text{ C}^2 \text{N}^{-1} \text{m}^{-2} \), the electric field between these sheets will be:

A bubble in glass slab (\( \mu = 1.5 \)) when viewed from one side appears at 5 cm and 2 cm from otherside, then the thickness of the glass slab is:

Match List - I with List - II.

List - I	List - II
(A) Australian marsupials	(I) Homologous organs
(B) Wings of butterfly and wings of a bird	(II) Natural selection
(C) Industrial melanism	(III) Adaptive radiation
(D) Forelimbs of Horse and Bat	(IV) Analogous organs

Choose the correct statements for ortho and para nitrophenol
(A) They can be separated by steam distillation
(B) o-Nitrophenol undergoes intramolecular hydrogen bonding
(C) P-Nitrophenol undergoes inter molecular hydrogen bonding
(D) p-Nitrophenol is less volatile
Choose the correct answer from the options given below:

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.
Heroin, commonly called smack is chemically _________ which is a white, odourless, bitter crystalline compound.

A spherical conductor placed in vacuum has capacitance of \( 3.14 \times 10^{-9} \, \text{F} \). Its radius will be:

Select the correct statement.

The area (in square units) bounded by the curve \(y=\cos x\) between \(x=0\) and \(x=2 \pi\) in first quadrant is equal to :