QJEEM14Ph3021
Physics - Class 11
• Chapter 12: Thermal Properties of matter
On heating water, bubbles being formed at the bottom of the vessel detach and rise. Take the bubbles to be spheres of radius R and making a circular contact of radius r with the bottom R and making a circular contact of radius r with the bottom of the vessel. If r << R and the surface tension of water is T , value of r just before bubbles detach is: (density of water is ρ w )
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QJEEM14Ph819b
Physics - Class 11
• Chapter 3: Units and Measurements
A student measured the length of a rod and wrote it as 3.50 cm. Which instrument did he use to measure it?
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QJEEM14Ph7ca8
Physics - Class 11
• Chapter 13: Thermodynamics
One mole of a diatomic ideal gas undergoes a cyclic process A B C as shown in figure. The process B C is adiabatic. The temperatures at A , B and C are 400 K , 800 K and 600 K respectively. Choose the correct statement :
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QJEEM14Ph5181
Physics - Class 11
• Chapter 6: Laws of motion
A block of mass m is placed on a surface with a vertical cross section given by y = x 3 6 . If the coefficient of friction is 0.5 , the maximum height above the ground at which the block can be placed without slipping is:
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QJEEM14Phec41
Physics - Class 11
• Chapter 16: Waves
A pipe of length 85 c m is closed from one end. Find the number of possible natural oscillations of air column in the pipe whose frequencies lie below 1250 H z . The velocity of sound in air is 340 m / s .
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QJEEM14Chb52e
Chemistry - Class 11
• Unit 13: States of Matter: Gases and Liquids
If Z is a compressibility factor, van der Waals equation at low pressure can be written as:
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QJEEM14Chcf31
Chemistry - Class 11
• Unit 8: Organic Chemistry – Some Basic Principles and Techniques
For the estimation of nitrogen, 1.4 g of organic compound was digested by Kjeldahl method and the evolved ammonia was absorbed in 60 mL of M/10 sulphuric acid. The unreacted acid required 20 ml of M/10 sodium hydroxide for complete neutralization. The percentage of nitrogen in the compound is:
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QJEEM14Ch3426
Chemistry - Class 11
• Unit 1: Some Basic Concepts of Chemistry
The ratio of masses of oxygen and nitrogen in a particular gaseous mixture is 1 : 4. The ratio of number of their molecule is:
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QJEEM14Ch44cb
Chemistry - Class 11
• Unit 6: Equilibrium
For the reaction SO 2 (g) + 1 2 O 2 ( g ) ⇋ SO 3 (g). if K P = K C (RT) x where the symbols have usual meaning then the value of x is: (assuming ideality)
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QJEEM14Ch9282
Chemistry - Class 11
• Unit 5: Thermodynamics
For complete combustion of ethanol, C 2 H 5 OH(l) + 3O 2 (g) → 2CO 2 (g) + 3H 2 O(l) the amount of heat produced as measured in bomb calorimeter, is 1364.47 kJ mol –1 at 25 o C. Assuming ideality the Enthalpy of combustion, Δ C H , for the reaction will be : (R = 8.314 kJ mol –1 )
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QJEEM14Ma5549
Mathematics - Class 11
• Chapter 14: Mathematical Reasoning
The statement ∼ ( p ↔∼ q ) is :
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QJEEM14Ma9d41
Mathematics - Class 11
• Chapter 14: Statistics
The variance of first 50 even natural numbers is
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QJEEM14Ma4139
Mathematics - Class 11
• Chapter 10: Straight Lines
Let a , b , c and d be non-zero numbers. If the point of intersection of the lines 4 a x + 2 a y + c = 0 and 5 b x + 2 b y + d = 0 lies in the fourth quadrant and is equidistant from the two axes then :
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QJEEM14Mab993
Mathematics - Class 11
• Chapter 3: Trigonometric Functions
Let f k ( x ) = 1 k ( sin k x + cos k x ) where x ∈ R and k ≥ 1. Then f 4 ( x ) − f 6 ( x ) equals :
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QJEEM14Maba8d
Mathematics - Class 11
• Chapter 11: Conic Sections
The locus of the foot of perpendicular drawn from the centre of the ellipse ${x^2} + 3{y^2} = 6$ on any tangent to it is :
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QJEEM14Ph6711
Physics - Class 12
• Chapter–5: Magnetism and Matter
The coercivity of a small magnet where the ferromagnet gets demagnetized is 3 × 10 3 A m − 1 . The current required to be passed in a solenoid of length 10 c m and number of turns 100 , so that the magnet gets demagnetized when inside the solenoid, is :
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QJEEM14Ph50bb
Physics - Class 12
• Chapter–12: Atoms
The radiation corresponding to $3 \to 2$ transition of hydrogen atom falls on a metal surface to produce photoelectrons. These electrons are made to enter a magnetic field $3 \times {10^{ - 4}}\,T.$ If the radius of the larger circular path followed by these electrons is $10.0$ $mm$ , the work function of the metal is close to:
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QJEEM14Ph5930
Physics - Class 12
• Chapter–5: Magnetism and Matter
A conductor lies along the $z$ -axis at $- 1.5 \le z < 1.5\,m$ and carries a fixed current of $10.0$ $A$ in $- {\widehat a_z}$ direction (see figure). For a field $\overrightarrow B = 3.0 \times {10^{ - 4}}\,{e^{ - 0.2x}}\,\,{\widehat a_y}\,\,T,$ find the power required to move the conductor at constant speed to $x=2.0$ $m$ , $y=0$ $m$ in $5 \times {10^{ - 3}}s.$ Assume parallel motion along the $x$ -axis.
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QJEEM14Phd532
Physics - Class 12
• Chapter–7: Alternating Current
In the circuit shown here, the point $'C'$ is kept connected to point $'A'$ till the current flowing through the circuit becomes constant. Afterward, suddenly, point $'C'$ is disconnected from point $'A'$ and connected to point $'B'$ at time $t=0.$ Ratio of the voltage across resistance and the inductor at $t=L/R$ will be equal to :
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QJEEM14Pha1e5
Physics - Class 12
• Chapter–10: Wave Optics
Two beams, $A$ and $B$ , of plane polarized light with mutually perpendicular planes of polarization are seen through a polaroid. From the position when the beam $A$ has maximum intensity (and beam $B$ has zero intensity), a rotation of polaroid through ${30^ \circ }$ makes the two beams appear equally bright. If the initial intensities of the two beams are ${{\rm I}_A}$ and ${{\rm I}_B}$ respectively, then ${{{{\rm I}_A}} \over {{{\rm I}_B}}}$ equals:
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QJEEM14Ma5ee4
Mathematics - Class 12
• Chapter 11: Differential Equations
If $g$ is the inverse of a function $f$ and $f'\left( x \right) = {1 \over {1 + {x^5}}},$ then $g'\left( x \right)$ is equal to:
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QJEEM14Ma8d56
Mathematics - Class 12
• Chapter 6: Three Dimensional Geometry
The angle between the lines whose direction cosines satisfy the equations $l+m+n=0$ and ${l^2} = {m^2} + {n^2}$ is :
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QJEEM14Ma239c
Mathematics - Class 12
• Chapter 9: Integrals
The integral $\int\limits_0^\pi {\sqrt {1 + 4{{\sin }^2}{x \over 2} - 4\sin {x \over 2}{\mkern 1mu} } } dx$ equals:
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QJEEM14Macf21
Mathematics - Class 12
• Chapter 4: Determinants
If $A$ is a $3 \times 3$ non-singular matrix such that $AA'=A'A$ and $B = {A^{ - 1}}A',$ then $BB'$ equals:
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QJEEM14Maac5d
Mathematics - Class 12
• Chapter 10: Applications of Integrals
The area of the region described by $A = \left\{ {\left( {x,y} \right):{x^2} + {y^2} \le 1} \right.$ and $\left. {{y^2} \le 1 - x} \right\}$ is :
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QJEEM14Chb2f0
Chemistry - Class 12
• Chapter 7: The p-Block Elements
Which one of the following properties is not shown by NO?
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QJEEM14Chef77
Chemistry - Class 12
• Chapter 2: Solutions
Consider separate solutions of 0.500 M C 2 H 5 OH(aq), 0.100 M Mg 3 (PO 4 ) 2 (aq), 0.250 M KBr(aq) and 0.125 M Na 3 PO 4 (aq) at 25 o C. Which statement is true about these solutions, assuming all salts to be strong electrolytes?
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QJEEM14Ch6e98
Chemistry - Class 12
• Chapter 10: Haloalkanes and Haloarenes
The major organic compound formed by the reaction of 1, 1, 1– trichloroethane with silver powder is:
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QJEEM14Ch7497
Chemistry - Class 12
• Chapter 14: Biomolecules
Which one of the following bases is not present in DNA?
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QJEEM14Ch329b
Chemistry - Class 12
• Chapter 15: Polymers
Which one is classified as a condensation polymer?
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