Recent questions tagged neet-2020-p2

Which of the following substituted phenols is the strongest acid?

What is the role of gypsum, CaSO4·2H2O in setting of cement? Identify the correct option from the following : (1) to slow down the setting process (2) to fasten the setting process (3) to provide water molecules for hydration process (4) to help to remove ...

A liquid compound (x) can be purified by steam distillation only if it is (1) Not steam volatile, immiscible with water (2) Steam volatile, immiscible with water (3) Not steam volatile, miscible with water (4) Steam volatile, miscible with water

Match the elements in Column I with methods of purification in Column II. Column I Column II (a) Boron (i) Van Arkel method (b) Tin (ii) Mond's process (c) Zirconium (iii) Liquation (d) Nickel (iv) Zone refining (1) (a)-(iii), (b)-(iv), (c)-(i), (d)-(ii) (2...

A person sitting in the ground floor of a building notices through the window, of height 1.5 m, a ball dropped from the roof of the building crosses the window in 0.1 s. What is the velocity of the ball when it is at the topmost point of the window ? (g-10 ...

The wave nature of electrons was experimentally verified by : (1) Davisson and Germer (2) de Broglie (3) Hertz (4) Einstein

Identify the function which represents a periodic motion. (1) e–ωt (2) eωt (3) loge(ωt) (4) sinωt + cosωt

Which of the following gate is called universal gate ? (1) NOT gate (2) OR gate (3) AND gate (4) NAND gate

The variation of electrostatic potential with radial distance r from the centre of a positively charged metallic thin shell of radius R is given by the graph

The power of a biconvex lens is 10 dioptre and the radius of curvature of each surface is 10 cm. Then the refractive index of the material of the lens is : (1) $3\over2$ (2) $4\over3$ (3) $9\over8$ (4) $5\over3$

A parallel plate capacitor having cross-sectional area A and separation d has air in between the plates. Now an insulating slab of same area but thickness d/2 is inserted between the plates as shown in figure having dielectric constant K(= 4). The ratio of ...

A plano-convex lens of unknown material and unknown focal length is given. With the help of a spherometer we can measure the : (1) refractive index of the material (2) focal length of the lens (3) radius of curvature of the curved surface (4) aperture of ...

A point mass 'm' is moved in a vertical circle of radius 'r' with the help of a string. The velocity of the mass is $\sqrt{7gr}$ at the lowest point. The tension in the string at the lowest point is (1) 1 mg (2) 6 mg (3) 7 mg (4) 8 mg

Calculate the acceleration of the block and trolly system shown in the figure. The coefficient of kinetic friction between the trolly and the surface is 0.05. (g = 10 m/s2, mass of the string is negligible and no other friction exists). (1) 1.00 m/s2 (2) 1....

If the critical angle for total internal reflection from a medium to vacuum is 45°, then velocity of light in the medium is : (1) 3 × 108 m/s (2) 1.5 × 108 m/s (3) $3\over\sqrt2$ × 108 m/s (4) $\sqrt2$ × 108 m/s

What happens to the mass number and atomic number of an element when it emits $\gamma$-radiation? (1) Mass number increases by four and atomic number increases by two. (2) Mass number decreases by four and atomic number decreases by two. (3) Mass number and...

The acceleration of an electron due to the mutual attraction between the electron and a proton when they are 1.6 Å apart is : (me = 9 10−31 kg, e = 1.6 10−19 C) (Take $1\over4\pi\epsilon_o$ = 9 109Nm2C−2) (1) 1025 m/s2 (2) 1024 m/s2 (3) 1023 m/s2 (4) ...

The angular speed of the wheel of a vehicle is increased from 360 rpm to 1200 rpm in 14 second. Its angular acceleration is : (1) 1 rad/s2 (2) 2π rad/s2 (3) 28π rad/s2 (4) 120π rad/s2

An object is placed on the principal axis of a concave mirror at a distance of 1.5 f (f is the focal length). The image will be at, (1) 3f (2) –3f (3) 1.5 f (4) –1.5f

What is the depth at which the value of acceleration due to gravity becomes $1\over n$ times the value that at the surface of earth? (radius of earth = R) (1) $R\over n$ (2) $R\over n^2$ (3) $R(n-1)\over n$ (4) $Rn\over (n-1)$

A wire of length L metre carrying a current of l ampere is bent in the form of circle. Its magnetic moment is (1) I L2/4π A m2 (2) I L2/4 A m2 (3) I πL2/4 A m2 (4) 2I L2/π A m2

The total energy of an electron in the nth stationary orbit of the hydrogen atom can be obtained by (1) $E_n=-13.6×n^2$ eV (2) $E_n={13.6\over n^2}$ eV (3) $E_n=-{13.6\over n^2}$ eV (4) $E_n=-{1.36\over n^2}$ eV

The angle of 1′ (minute of arc) in radian is nearly equal to (1) 1.75 × 10–2 rad (2) 2.91 × 10–4 rad (3) 4.85 × 10–4 rad (4) 4.80 × 10–6 rad

The de Broglie wavelength of an electron moving with kinetic energy of 144 eV is nearly (1) 102 × 10–2 nm (2) 102 × 10–3 nm (3) 102 × 10–4 nm (4) 102 × 10–5 nm

Three identical spheres, each of mass M, are placed at the corners of a right angle triangle with mutually perpendicular sides equal to 2 m (see figure). Taking the point of intersection of the two mutually perpendicular sides as the origin, find the ...

A light bulb and an inductor coil are connected to an ac source through a key as shown in the figure below. The key is closed and after sometime an iron rod is inserted into the interior of the inductor. The glow of the light bulb (1) increases (2) ...

Three stars A, B, C have surface temperatures TA, TB, TC respectively. Star A appears bluish, star B appears reddish and star C yellowish. Hence, (1) TA > TC > TB (2) TA > TB > TC (3) TB > TC > TA (4) TC > TB > TA

A liquid does not wet the solid surface if angle of contact is (1) zero (2) equal to 45° (3) equal to 60° (4) greater than 90°

The electric field at a point on the equatorial plane at a distance r from the centre of a dipole having dipole moment $\vec{p}$ is given by, (r >> separation of two charges forming the dipole, $\epsilon_0$ - permittivity of free space) (1) $\vec{E}=-{\vec{...

The efficiency of a Carnot engine depends upon (1) the temperature of the source only (2) the temperature of the sink only (3) the temperatures of the source and sink (4) the volume of the cylinder of the engine