In the given figure, the potentiometer wire, AB has a resistance of 5 \( \Omega \) and length 10 m. The balancing length AJ for 0.4 V is nearly:

The electric field amplitude of an electromagnetic wave is \(100 N C ^{-1}\) and its frequency is 50 MHz . What is the magnitude of wave vector \(k\), (given speed of electromagnetic wave is \(3 \times 10^8 m s ^{-1}\) )

The transfer of integral number of ____________ is one of the evidence of quantization of electric charge.

An ammeter of resistance 5 \( \Omega \) reads up to 1 A. The value of the shunt required to increase its range to 5 A will be

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

In a series RLC circuit at resonance
(A) Impedance is maximum
(B) \( X_c = X_L \)
(C) Z = R
(D) \( \omega = \frac{1}{\sqrt{LC}} \)
Choose the correct answer from the options given below:

The following have zero average value in a plane electromagnetic wave

When white light consisting of wavelengths ranging from 400 nm to 700 nm passes through water (u = 4/3), then the wavelength range in water will be :

\(\int \frac{d x}{2 \sin ^2 x+5 \cos ^2 x}\) is equal to

The number of years required for a sum of money to get tripple at the effective rate of \(4\%\) is : (Given \((1.04)^{28}=3\) )

Kirchhoff's second law is based on the law of conservation of

Read the passage carefully and answer the given questions.
Recombinant DNA Technology Asexual reproduction preserves the genetic information, while sexual reproduction permits variation. Traditional hybridization procedures used in plants and animals breeding very often lead to inclusion and multiplication of undesirable genes along with the desired genes. The techniques of genetic engineering, which include creation of recombinant DNA, use of gene cloning and gene transfer, overcome this limitation and allow us to isolate and introduce only one or a set of desirable genes without introducing genes into the target organism.
In Recombinant DNA Technology, what is the role of the "selectable marker gene"?

The arrangement of the nuclei in a normal embryo sac from the chalazal to micropylar end in dicots is -