JEE (MAINS) 2017 with Solutions
The formation of which of the following polymers involves hydrolysis reaction
(1) Terylene (2) Nylon 6 (3) Bakelite(4) Nylon 6, 6
The Tyndall effect is observed only when following conditions are satisfied :
(a) The diameter of the dispersed particles is much smaller than the wavelength of the light used.
(b) The diameter of the dispersed particle is not much smaller than the wavelength of the light used.
(c) The refractive indices of the dispersed phase and dispersion medium are almost similar in
(d) The refractive indices of the dispersed phase and dispersion medium differ greatly in
(1) (b) and (c) (2) (a) and (d) (3) (b) and (d) (4) (a) and (c)
3-Methyl-pent-2-ene on reaction with HBr in presence of peroxide forms an addition product. The number of possible stereoisomers for the product is:
(1) Four (2) Six (3) Zero (4) Two
Twenty meters of wire is available for fencing off a flower-bed in the form of a circular sector. Then the maximum area (in sq. m) of the flower-bed, is :
(1) 25 (2) 30 (3) 12.5 (4) 10
In a Young’s double slit experiment, slits are separated by 0.5 mm, and the screen is placed 150 cm away. A beam of light consisting of two wavelengths, 650 nm and 520 nm, is used to obtain interference fringes on the screen. The least distance from the common central maximum to the point where the bright fringes due to both the wavelengths coincide is:
(1) 7.8 mm (2) 9.75 mm (3) 15.6 mm (4) 1.56 mm