Two coherent light beams of intensities I and 4 I are superimposed. The maximum and minimum possible intensities in the resulting pattern are :

A battery of emf 3 V and internal resistance r is connected in series with a resistor of \( 55 \text{ } \Omega \). An ammeter of resistance \( 2 \text{ } \Omega \) connected in circuit reads 50 mA. The value of r is

The critical angle of incidence \( i_c \) for a ray incident from a denser to a rarer medium, is that angle for which

The magnetisation at the centre of a bar magnet (magnetic length 10 cm), having pole strength 6.3 A m, and area of cross-section \(A = 0.70 \text{ cm}^2\) is

The equivalent resistance of the network shown in figure between the points a and b will be

Two identical short bar magnets each of magnetic moment \( 12.5 \text{ Am}^2 \) are placed with 10 cm separation between their centers as shown in the figure. The magnitude of magnetic field at O is

A proton, an electron, a neutron and an alpha particle have the same energy. Their de Broglie's wavelengths are given below:
(A) \( \lambda_{proton} \)
(B) \( \lambda_{electron} \)
(C) \( \lambda_{neutron} \)
(D) \( \lambda_{alpha} \)
Arrange these wavelengths in decreasing order. Choose the correct answer from the options given below:

Amit, Sumit and Puneet were doing shooting.
Amit hits the target 4 times in 5 shots, Sumit hits the target 3 times in 4 shots and Puneet hits the target 2 times in 3 shots.
Then the probability that Amit, Sumit and Puneet all may hit the target is:

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 :

The magnetic field in a plane electromagnetic wave is given by \( B_y = 2 \times 10^{-7} \sin(0.5 \times 10^3 x + 1.57 \times 10^{11} t) \text{ T} \). The frequency of the wave is

The first isolated restriction endonuclease was:

Answer the question on the basis of passage given below:
Second period elements of p-Block differs from the rest of their group members due to their small atomic size, high electronegativity, high ionization enthalpy and absence of d-orbitals. The elements from the second period like C, N, O have unique property of forming \(p \pi-p \pi\) multiple bonds whereas other heavier elements of p-block form \(d \pi-p \pi\) multiple bonds. This changes the properties of second period elements to great extent. Also the single bond strength of the p-block elements with their own atoms gets affected by their atomic size and presence of lone pairs.
Inert pair effect also affects the properties of the p-Block elements especially for those elements which are present from 4th period onward and this happens due to poor screening effect of inner (n-1)d subshell electrons.
Catenation tendency of Nitrogen is weaker than Phosphorus, because

\(\Lambda_m^o\) for \(NaCl , HCl\), and NaAc are \(126.4,425.9\) and \(91.0 S cm ^2 mol^{-1}\), respectively. \(\Lambda_m^o\) for HAc is