In a Young's double slit experiment, interference fringes were produced on a screen placed 1.8 m from the two slits 0.3 mm apart and illuminated by light of wavelength 600 nm. The fringe width is

The distance estimation for which ray optics is good approximation for an aperture of 3 mm and wavelength 300 nm would be :

The current and voltage in an a. c. circuit are given as
\( I = 50 \sin(50t) \text{ mA} \),
\( V = 100 \sin(50t + \pi/3) \text{ volt} \).
The power dissipated in the circuit is

An electron is projected into a magnetic field of flux density \( 10 \text{ Wb/m}^2 \) with a velocity of \( 3 \times 10^7 \text{ m/s} \) at an angle of \( 30^{\circ} \) to the field. The magnetic force on the electron is:

Identify the correct statement(s) among the following:
(A) If three electrical cells each of emf, E and internal resistance r are connected in series to a resistance R, the current drawn from them is 3E/(R+3r).
(B) If these three cells are connected in parallel combination, across resistance R then the current drawn will be E/(3R+r).
(C) If the two cells are connected in series and then one in parallel which are then connected across resistance R, then the current drawn will be 2E/(2R+2r).
(D) In a mixed grouping of cells, current will be maximum when total external resistance is equal to total equivalent internal resistance.
Choose the correct answer from the options given below :

The energy of electron in the first excited state of Hydrogen atom is -3.4 eV. The potential energy of this electron is :

An induced emf is produced when a magnet is plunged into a coil. The magnitude of the induced emf is independent of

Which of the following biofertilisers are free living in the soil?
(A) Anabaena
(B) Azospirillum
(C) Rhizobium
(D) Azotobacter
Choose the correct answer from the options given below:

Which of the following in NOT true for Bt toxin ?
(A) It is produced by Bacillus thuringiensis
(B) It is produced in active form
(C) It exist as inactive protoxin
(D) It is used to produce nematode-resistant plants
Choose the correct answer from the options given below :

Which of the following is NOT a sexually transmitted disease?

Difference between the maximum and minimum value of the objective function \(Z=5 x+3 y\), subject to the constraints: \(3 x+5 y \leq 15 ; 5 x+2 y \leq 10 ; x, y \geq 0\) is:

Answer the question on the basis of passage given below :
Adsorption is the phenomenon of attracting and retaining the molecules of a substance on the surface of a solid resulting into a higher concentration on the surface than in the bulk. The substance adsorbed is known as adsorbate and the substance on which adsorption takes place is called adsorbent. In physisorption adsorbate is held to the adsorbent by weak van der Waals forces and in chemisorption by strong chemical bond.
Out of Milk, butter, ice cream, fruit juice and lemonade. Identify the one which is not a colloid.

Which property is observed in an emulsion ?