The linear charge density of an infinite line charge producing a uniform electric field of \(9 \times 10^6 N / C\) at a distance of 2 cm is :
(Take permittivity of vacuum \(\epsilon_0=8.85 \times 10^{-12} C ^2 N^{-1} m^{-2}\) )

When a piece of metal is illuminated by monochromatic light of wavelength λ, the stopping potential for photoelectric current is 2.5 V0. When the same surface is illuminated by light of wavelength 1.5 λ, the stopping potential becomes V0. The value of threshold wavelength for photoelectric emission is:

Rohit has been given two converging lenses of focal lengths 1.25 cm and 5 cm, respectively to design a compound microscope. If it is desired to have a magnification of 30, what would be the separation between the objective and the eyepiece when the final image is formed at the least distance of distinct vision?

In Young's double slit experiment, slits are illuminated by light of wavelength 650 nm. The slits are 0.13 cm apart and the screen is placed 1.2 m away. What will be the separation of the adjacent maxima?

In a moving coil galvanometer, the coil is wound over a metallic frame in order to

In the Block diagram of a generalised communication system, the elements are given below. The correct order of elements should be :
(A) Transmitter
(B) Information Source
(C) User of Information
(D) Channel
(E) Receiver
Choose the correct answer from the options given below:

The resistivity of the material of a wire of length 15 m, area of cross-section \( 6 \times 10^{-7} \text{ m}^2 \) and resistance 10 \(\Omega\) will be

Let \(A, B, C, D\) and \(E\) be matrices of \(2 \times n, 3 \times k, 2 \times p\),
\(2 \times p\) and \(3 \times 3\) respectively.
Choose the correct statement(s) from the following :
(A) \(E B+D B\) will be defined if \(k=3, p=n\).
(B) \(E(3 \times 3) \cdot B(3 \times k) \rightarrow(3 \times k) \rightarrow n \times 3\).
(C) If \(n=p=2\), then the order of the matrix \(5 A^2-3 C\) is \(2 \times 2\).
(D) If \(n=p\), then the order of the matrix \(5 A^2-3 C\) is \(2 \times 3\).
Choose the correct answer from the options given below :

Two capacitors of capacitances \(8 \mu F\) and \(20 \mu F\) are connected in series with a battery. The voltage across the \(8 \mu F\) capacitor is 5 V . The total battery voltage is:

Arrange the following cells according to their order of development in testis during spermatogenesis.
(A) Secondary spermatocytes
(B) Spermatids
(C) Primary spermatocytes
(D) Spermatogonia
Choose the correct answer from the options given below:

Read the passage carefully and answer the questions
Replacement of a hydrogen atom in a hydrocarbon by an alkoxy or carboxyl group yields a class of compounds known as ethers. Ethers are classified as symmetrical or unsymmetrical on the basis of groups attached to the oxygen atoms. Diethyl ether, a symmetrical ether, has been widely used as an inhalation anesthetic. Ethers can be prepared by acid catalyzed intermolecular dehydration of alcohols and Williamson's synthesis. Acid catalyzed dehydration of alcohols is not generally preferred as it gives a mixture of elimination and substitution products. In Williamson's synthesis, an alkyl halide is allowed to react with sodium alkoxide. Ethers containing substituted Alkyl groups may also be prepared by this method. The C-O bond in ether is weakly polar and is cleaved under drastic conditions with excess of hydrogen halides. In electrophilic substitution, the alkoxy group deactivates the aromatic ring and directs the incoming group to ortho and para positions.
Which type of ether is anisole ?

Which one of the followings is an auto-immune disease?

Identify the incorrect statement about the human genome -