Two point charges \( +4 \mu C \) and \( -2 \mu C \) are placed at a certain distance in air. They experience an attractive force \( F \). If they are brought in contact with each other and then separated to the same distance, the new repulsive force between them will be :

The ratio of the de-Broglie wavelengths associated with protons accelerated through a potential of 128 V and alpha particles accelerated through a potential of 64 V will be

Current carrying wire produces:

For which of the following, a capacitor acts as an infinite resistance component in the circuit?

A conducting circular loop is placed in a uniform magnetic field of 10 T with its plane normal to the field. Now, the radius of the loop starts shrinking at the rate 5 mm/s. When the radius is 5 cm then the induced emf is

An electron is moving at a velocity of 100 m/s along the X-axis in the presence of an electric field of 30 V/m directed along the Y-axis and a magnetic field of 300 G directed along the Z axis. The magnitude and direction of force acting on the electron is (Given: the charge on the electron is "e")

If the two ends of a p-n junction are joined by a wire:

A coil of inductance 0.50 H and resistance 100 \( \Omega \) is connected to 240 V, 50 Hz supply. The maximum current in the coil is:

Which of the following complexes are square planar?
(A) \(\left[ Ni ( CN )_4\right]^{2-}\)
(B) \(\left[ NiCl _4\right]^{2-}\)
(C) \(\left[ PtCl _4\right]^{2-}\)
(D) \(\left[ PdCl _4\right]^{2-}\)
Choose the correct answer from the options given below

Read the passage carefully and answer the questions:
The degeneracy of the \(d\) orbitals has been removed due to ligand electron-metal electron repulsions in the octahedral complex to yield three orbitals of lower energy, \(t_2\), set and two orbitals of higher energy, \(e_g\) set. This splitting of the degenerate levels due to the presence of ligands in a definite geometry is termed as crystal field splitting and the energy separation is denoted by \(\Delta_0\). Thus energy of the two \(e_g\), orbitals will increase by \((3 / 5) \Delta_0\) and that of three \(t_{2 g}\) will decrease by \((2 / 5) \Delta_0\). The crystal field splitting \(\Delta_0\) depends upon the field produced by the ligand and charge on the metal ion. Some ligands are able to produce strong fields, in which case the splitting will be large, whereas others produce weak fields and consequently result in small splitting of \(d\) orbitals. Relative magnitude of crystal field splitting energy \(\Delta_0\) and pairing energy, \(P\) (energy required for electron pairing in a single orbital) determine the formation of low spin ( \(\Delta_0>P\) ) or high spin ( \(\Delta_0<P\) ) complex. In tetrahedral coordination entity formation, the \(d\)-orbital splitting is inverted and is smaller as compared to the octahedral field splitting. The crystal field theory attributes the colour of the complex to \(d-d\) transition of the electron. The colour of the coordination compounds depends on the crystal field splitting. In the absence of ligand, crystal field splitting does not occur and hence the substance is colourless.
Choose the correct statement from the following:

If the matrix \(\left[\begin{array}{ccc}2 & -1 & 3 \\ \lambda & 0 & 7 \\ -1 & 1 & 4\end{array}\right]\) is not invertible, then the value of \(\lambda\) is :

A conductor is placed along z-axis carrying current in z direction in uniform magnetic field directed along y-axis. The magnetic force acting on the conductor is directed along:

DNA recombinant technology involves the use of restriction endonucleases. After having cloned the gene of interest and having optimised the conditions to induce the expression of the target protein, one has to consider producing it on a large scale. The cells harbouring cloned genes of interest may be grown on a small scale in the laboratory. In order to link the alien DNA, the vector needs to have very few, preferably single, recognition sites for the commonly used restriction enzymes. Presence of more than one recognition sites within the vector will generate several fragments, which will complicate the gene cloning. In Biolistics or gene gun method cells are bombarded with high velocity micro particles of gold or tungsten coated with DNA. The ligation of alien DNA is carried out at a restriction site present in one of the two antibiotic resistance genes. For example, you can ligate a foreign DNA at the BamH I site of tetracycline resistance gene in the vector pBR322. Since the DNA is enclosed within the membranes, we have to break the cell open to release DNA along with other macromolecules such as RNA, proteins, polysaccharides and also lipids. The RNA can be removed by treatment with ribonuclease whereas proteins can be removed by treatment with protease. Other molecules can be removed by appropriate treatments and purified DNA ultimately precipitates out after the addition of chilled ethanol.
Which one of the following enzymes works as molecular glue?