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questions
List of practice Questions
An electric dipole of dipole moment is 6.0 x 10
-6
Cm placed in a uniform electric field of 1.5 x 10
3
NC
-
1 in such a way that dipole moment is along electric field. The work done in rotating dipole by 180º in this field will be _____mJ.
JEE Main - 2023
JEE Main
Physics
Electric Field
Three bulbs are filled with CH4, CO2 and Ne as shown in the picture. The bulbs are connected through pipes of zero volume. When the stopcocks are opened and the temperature is kept constant throughout, the pressure of the system is found to be_______atm. (Nearest integer)
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Chemistry
subshell electronic configuration
The number of following statement/s which is/are
\(\text{\underline{ incorrect}}\)
is______
(A) Line emission spectra are used to study the electronic structure
(B) The emission spectra of atoms in the gas phase show a continuous spread of wavelength from red to violet
(C) An absorption spectrum is like the photographic negative of an emission spectrum
(D) The element helium was discovered in the sun by spectroscopic method.
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Chemistry
atomic spectra
When a 60 W electric heater is immersed in a gas for 100s in a constant volume container with adiabatic walls, the temperature of the gas rises by 5°C. The heat capacity of the given gas is_____J K
-1
(Nearest integer).
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JEE Main
Chemistry
Ideal gas equation
The vapour pressure vs. temperature curve for a solution solvent system is shown below.
The boiling point of the solvent is _____°C.
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Chemistry
Solutions
The titration curve of weak acid vs. strong base with phenolphthalein as indictor is shown below. The K
phenolphthalein
= 4 × 10
-10
.
Given: log2 = 0.3
The number of following statements which is/are correct about phenolphthalein is______
A. It can be used as an indicator for the titration of weak acid with weak base.
B. It begins to change colour at pH = 8.4
C. It is a weak organic base
D. It is colourless in acidic medium.
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Chemistry
Acids and Bases
Molar mass of the hydrocarbon (X) which on ozonolysis consumes one mole of O3 per mole of (X) and gives one mole each of ethanal and propanone is _______ g mol-1
(Molar mass of C : 12 g mol-1 , H : 1 g mol-1)
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Chemistry
molecular mass of polymers
The number of points, where the curve y = x
5
– 20x
3
+ 50x + 2 crosses the x-axis, is _____.
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Mathematics
Area under Simple Curves
Let a curve y = f(x), x ∈ (0, ∞) pass through the points
\(p ( 1\frac{3 }{2} )\)
and Q
\( ( a,\frac{1 }{2} )\)
. If the tangent at any point R(b, f(b)) to the given curve cuts the y-axis at the point S (0, c) such that bc = 3, then (PQ)
2
is equal to ______.
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Mathematics
Tangents and Normals
Let f (x) =
\(\frac{x}{ (1+x ^n )^{\frac{1}{n} }}\)
, x∈R-{-1}, n∈N. n>2.
If f
n
(x) = (fofof____upto n times) (x), then
\(lim ∫^1_ {n→∞ 0} x^{n-2}\)
( f
n
(x))dx is equal to ___.
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JEE Main
Mathematics
types of differential equations
Let the eccentricity of an ellipse
\(\frac{x^2}{a^2} + \frac{y^2}{b^2} = 1\)
, is reciprocal to that of the hyperbola 2x
2
-2y
2
=1. if the ellipse intersects the hyperbola at right angles, then square of length of the latus-rectum of the ellipse is___.
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Mathematics
Ellipse
If the lines
\(\frac{x−1}{2}=\frac{2−y }{−3} =\frac{ z−3 }{α}\)
and
\( \frac{x−4 }{5} =\frac{y−1}{ 2}= \frac{z}{ β}\)
intersect, then the magnitude of the minimum value of 8αβ is ___.
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Mathematics
types of differential equations
Let the mean and variance of the frequency distribution
x
i
2
4
6
8
10
12
14
16
f
i
4
4
α
15
8
β
4
5
are 9 and 15.08 respectively, then the value of α
2
+β
2
-αβ is ____.
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Mathematics
Mean Deviation
The value of tan 9°-tan27°-tan63°+tan81° is____.
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Mathematics
types of differential equations
A body is dropped on ground from a height ‘h
1
’ and after hitting the ground, it rebounds to a height ‘h
2
’ If the ratio of velocities of the body just before and after hitting ground is
\(4\)
. then percentage loss in kinetic energy of the body is
\(\frac{x}{4}\)
. The value of x is_____.
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JEE Main
Physics
Kinetic Energy
A metal block of mass m is suspended from a rigid support through a metal wire of diameter 14 mm. The tensile stress developed in the wire under equilibrium state is 7× 10
5
Nm
-2
. The value of mass m is ___ kg. (Take, g = 9.8 ms-2 and π =
\(\frac{ 22}{7}\)
)
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JEE Main
Physics
Centre of mass
Two concentric circular coils with radii 1 cm and 1000 cm, and number of turns 10 and 200 respectively are placed coaxially with centers coinciding. The mutual inductance of this arrangement will be _____× 10
-8
H.
(Take, π
2
= 10)
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Physics
Uniform Circular Motion
A beam of light consisting of two wavelengths 7000 Å and 5500 Å is used to obtain interference pattern in Young's double slit experiment. The distance between the slits is 2.5 mm and the distance between the plane of slits and the screen is 150 cm. The least distance from the central fringe, where the bright fringes due to both the wavelengths coincide, is n × 10
-5
m. The value of n is_____.
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Physics
Waves
Experimentally it is found that 12.8 eV energy is required to separate a hydrogen atom into a proton and an electron. So the orbital radius of the electron in a hydrogen atom is
\(\frac{ 9}{x} x 10^{-10}\)
m. The value of the x is _____.
(1eV = 1.6 x 10
-19
J,
\(\frac{1}{4π∈_0}\)
= 9 x 10
9
NM
2
/ C
2
and electronic charge = 1.6 x 10
-19
JC)
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Physics
Conservation of energy
As shown in the figure, the voltmeter reads 2V across 5Ω resistor. The resistance of the voltmeter is_____Ω.
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Physics
Resistance
As shown in the figure, two parallel plate capacitors having equal plate area of 200 cm2 are joined in such a way that a ≠ b. The equivalent capacitance of the combination is x ∈0 F. The value of x is_____.
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JEE Main
Physics
Combination of capacitors
A simple pendulum with length 100 cm and bob of mass 250 g is executing S.H.M. of amplitude 10cm. The maximum tension in the string is found to be
\(\frac{x}{40}\)
N. The value of x is___.
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JEE Main
Physics
tension
Number of crystal systems from the following where body centred unit cell can be found, is......
Cubic, tetragonal, orthorhombic, hexagonal, rhombohedral, monoclinic, triclinic.
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JEE Main
Chemistry
Chemical Reactions of Alcohols Phenols and Ethers
The number of species having a square planar shape from the following is __
\(XeF_4, SF_4, SiF_4, BF^-_4 BrF^-_4,[Cu(NH_3)_4]^{2+}, [FeCl_4]^{2-}, [PtCl_4]^{2-}\)
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Chemistry
Chemical Reactions of Alcohols Phenols and Ethers
Consider the following date
Heat of combustion of H
2
(g) = -241.8 kJ mol
-1
Heat of combustion of C(s) = -393.5 kJ mol
-1
Heat of combustion of C
2
H
5
OH(1) = -1234.7 kJ mol
-1
The heat of formation of C
2
H
5
OH(1) is (-) ____ kJ mol
-1
(Nearest integer)
JEE Main - 2023
JEE Main
Chemistry
Chemical Reactions of Alcohols Phenols and Ethers
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