Light of wavelength 300 nm is used in an experiment on photoelectric effect with lithium having a work function of 2.7 eV. The maximum kinetic energy of ejected photo-electrons will be

Electric field at a point due to a uniformly charged infinite plane sheet is

A short bar magnet of magnetic dipole moment \( 10^{-5} \text{ A m}^{2} \) is kept in a uniform magnetic field \( 3 \times 10^{-4} \text{ T} \) at an angle of \( 30^{\circ} \). The torque acting on it is :

A cell of e.m.f 4V and internal resistance \(0.2 \Omega\) is connected to \(1.8 \Omega\) external resistance. The potential difference across the terminal of the cell will be:

The figure shows an arrangement of bar magnets in different configurations. Each bar magnet has a magnetic dipole moment m. The figure which has the maximum magnetic dipole moment _______ .

Choose the correct option from the following:
(A) The internal resistance of a cell depends on its distance between electrodes and on the area of the electrodes.
(B) The emf of a cell is measured when it is used in series in an electrical circuit carrying current I.
(C) If a cell of emf E and of internal resistance r is providing current/through a resistance R then the potential difference across the cell is V = I(R + r).
(D) The emf of a cell is 1 V, if 1 J of work is done by the cell to drive 1 C of charge in the whole circuit.
Choose the correct answer from the options given below:

A 50 cm long air core solenoid has a 2 cm radius and 500 turns. The self-inductance of the solenoid would be (given \(\mu_0=4 \pi \times 10^{-7} \operatorname{Tm} * A^{-1}\) and \(\pi^2=10\) )

Read the following paragraph carefully and answer the given questions.
In the year 1963 the two enzymes responsible for restricting the growth of bacteriophage in E. coli were isolated. The first restriction endonuclease - Hind II, whose functioning depended on a specific DNA nucleotide sequence was characterized five years later. It was found that Hind II always cut DNA molecules at a particular point by recognizing a specific sequence of six base pairs. This specific base sequence is known as the recognition sequence for Hind II. Besides Hind II, today we know more than 900 restriction enzymes that have been isolated from over 230 strains of bacteria, each of which recognize different recognition sequences.
When DNA from different sources is cut by the same restriction enzymes, the resultant DNA fragments have the :

If the points (-1,-1,2), (2, m, 5) and (3, 11, 6) are collinear, then m equals

The solution set of the inequality \(2x + 3y < 4\) is :

Chlorine is extracted from brine by:

Current and voltage in an a. c. circuit are given as
\( I = 10 \sin(50t -
\frac{\pi}{2}) \text{ A} \)
\( V = 200 \sin(50t) \text{ V} \) (t represents time)
The power dissipated in the circuit is

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.
Which of the following technique is not very useful to detect the cancers of internal organs?