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The tendency of BF3, BCl3 and BBr3 to behave as Lewis acid decreases in the sequence (a) BF3 > BCl3 > BBr3 (b) BCl3 > BF3 > BBr3 BCl3 and BBr3 to behave as Lewis acid decreases in the sequence (a) BF3 > BCl3 > BBr3 (b) BCl3 > BF3 > BBr3 The tendency of [...]

Borax is used as cleansing because on dissolving in water it gives (a) Alkaline solution (b) Acidic solution (c) Bleaching solution Borax is used as cleansing because on dissolving in water it gives (a) Alkaline solution (b) Acidic solution (c) Bleaching solution November 17, 2020 Category: Uncategorised (JEE Advanced Physics by BM Sharma + GMP [...]

The mean distance of sun from the earth is 1.5×10^8 km. The time taken by light to reach earth from the sun is The mean distance of sun from the earth is 1.5×10^8 km. The time taken by light to reach earth from the sun is November 17, 2020 Category: Cengage NEET by C.P Singh [...]

A concave mirror of radius of curvature 60 cm is placed at the bottom of a tank, containing water up to height of 20 cm. The mirror faces upwards with its axis vertical. Solar light falls normally on the surface of water and the image of sun is formed. If u=4/3, then with the observer [...]

A pile driven into the bottom of a lake extends 3m above the bottom of a lake and 1m above the surface of water (.aμω)=4/3. If the sun is 30^∘ above the horizon, then the length of the shadow of the pile on the bottom is approximately A pile driven into the bottom of a [...]

A concave mirror is placed at the bottom of an empty tank with face upward and axis vertical. When sunlight falls normally on the mirror, it is focused at distance of 32 cm from the mirror. If the tank filled with water (μ = 3/4 ) up to a height 20 cm then the sunlight [...]

A container is filled with water (μ=1.33) up to a height of 33.25 cm. A concave mirror is placed 15 cm above the water level and the image of an object placed at the bottom is formed 25 cm below the water level. The focal length of the mirror is A vessel of depth d [...]

A microscope is focused on a mark on a piece of paper and then a slab of glass of thickness 3 cm and refractive index 1.5 is placed over the mark. How should the microscope be moved to get the mark in focus again A vessel of depth d is half filled with a liquid [...]

A slab of glass of refractive index 1.5 and thickness 3cm is placed with the faces perpendicular to the principle axis of a concave mirror. If the radius of curvature of the mirror is 10cm, the distance at which an object must be placed from the mirror so that the image coincides with the object [...]

In diborane, the two H – B – H angles are nearly (a) 60, 120 (b) 95, 120 (c) 95, 150 (d) 120 , 180 120 (b) 95 120 (c) 95 150 (d) 120 180 In diborane the two H - B - H angles are nearly (a) 60 November 17, 2020 Category: Uncategorised (JEE [...]