A ball is made of a material
Question: A ball is made of a material of density $\rho$ where $\rho_{\text {oil }}\rho\rho_{\text {water }}$ with $\rho_{\text {oil }}$ and $\rho_{\text {water }}$ representing the densities of oil and water, respectively. The oil and water are immiscible. If the above ball is in equilibrium in a mixture of this oil and water, which of the following pictures represents its equilibrium position ?Correct Option: , 3 Solution:...
Read More →A smooth block is released at rest on a
Question: A smooth block is released at rest on a $45^{\circ}$ incline and then slides a distance $\mathrm{d}$. The time taken to slide is $\mathrm{n}$ times as much to slide on rough incline than on a smooth incline. The coefficient of friction is- $\mu_{k}=1-\frac{1}{n^{2}}$$\mu_{k}=\sqrt{1-\frac{1}{n^{2}}}$$\mu_{s}=1-\frac{1}{n^{2}}$$\mu_{\mathrm{s}}=\sqrt{1-\frac{1}{\mathrm{n}^{2}}}$Correct Option: 1 Solution:...
Read More →A thin convex lens made from crown glass
Question: A thin convex lens made from crown glass $\left(\mu=\frac{3}{2}\right)$ has focal length $f$. When it is measured in two different liquids having refractive indices $\frac{4}{3}$ and $\frac{5}{3}$, it has the focal length $f_{1}$ and $f_{2}$ respectively. The correct relation between the focal lengths is :$f_{2}f$ and $f_{1}$ becomes negative$f_{1}$ and $f_{2}$ both become negative$f_{1}=f_{2}f$$f_{1}f$ and $f_{2}$ become negativeCorrect Option: , 4 Solution:...
Read More →The coercivity of a small magnet where the ferromagnet gets demagnetized is
Question: The coercivity of a small magnet where the ferromagnet gets demagnetized is $3 \times 10^{3} \mathrm{~A} \mathrm{~m}{ }^{-1}$. The current required to be passed in a solenoid of length $10 \mathrm{~cm}$ and number of turns 100 , so that the magnet gets demagnetized when inside the solenoid, is :3 A6 A30 mA60 mACorrect Option: 1 Solution:...
Read More →The graph between angle of deviation
Question: The graph between angle of deviation $(\delta)$ and angle of incidence (i) for a triangular prism is represented by :Correct Option: , 3 Solution: Theoritical...
Read More →Two short bar magnets of length $1 mathrm{~cm}$ each have magnetic moments
Question: Two short bar magnets of length $1 \mathrm{~cm}$ each have magnetic moments $1.20 \mathrm{Am}^{2}$ and $1.00 \mathrm{Am}^{2}$ respectively. They are placed on a horizontal table parallel to each other with their $\mathrm{N}$ poles pointing towards the South. They have a common magnetic equator and are separated by a distance of $20.0$ $\mathrm{cm}$. The value of the resultant horizontal magnetic induction at the midpoint $\mathrm{O}$ of the line joining their centres is close to:- (Hor...
Read More →Diameter of a plano-convex lens is 6 cm and thickness at the centre is 3 mm.
Question: Diameter of a plano-convex lens is $6 \mathrm{~cm}$ and thickness at the centre is $3 \mathrm{~mm}$. If speed of light in material of lens is $2 \times 10^{8} \mathrm{~m} / \mathrm{s}$, the focal length of the lens is : [JEE-Mains- 2013]$15 \mathrm{~cm}$$20 \mathrm{~cm}$$30 \mathrm{~cm}$$10 \mathrm{~cm}$Correct Option: , 3 Solution:...
Read More →An object 2.4 m in front of a lens forms a sharp image on a film 12 cm behind the lens.
Question: An object $2.4 \mathrm{~m}$ in front of a lens forms a sharp image on a film $12 \mathrm{~cm}$ behind the lens. A glass plate $1 \mathrm{~cm}$ thick, of refractive index $1.50$ is interposed between lens and film with its plane faces parallel to film. At what distance (from lens) should object be shifted to be in sharp focus on film ?$5.6 \mathrm{~m}$$7.2 \mathrm{~m}$$2.4 \mathrm{~m}$$3.2 \mathrm{~m}$Correct Option: 1 Solution:...
Read More →All the graphs below
Question: All the graphs below are intended to represent the same motion. One of them does it incorrectly. Pick it up.Correct Option: 1 Solution:...
Read More →An object 2.4 m in front of a lens forms a sharp image on a film 12 cm behind the lens.
Question: A beaker contains water up to a height $\mathrm{h}_{1}$ and kerosene of height $\mathrm{h}_{2}$ above watger so that the total height of (water + kerosene) is $\left(h_{1}+h_{2}\right)$. Refractive index of water is $\mu_{1}$ and that of kerosene is $\mu_{2}$. The apparent shift in the position of the bottom of the beaker when viewed from above is :-$\left(1-\frac{1}{\mu_{1}}\right) \mathrm{h}_{2}+\left(1-\frac{1}{\mu_{2}}\right) \mathrm{h}_{1}$$\left(1+\frac{1}{\mu_{1}}\right) \mathrm...
Read More →A block rests on a rough inclined plane making an angle of
Question: A block rests on a rough inclined plane making an angle of $30^{\circ}$ with the horizontal. The coefficient of static friction between the block and the plane is $0.8$. If the frictional force on the block is $10 \mathrm{~N}$, the mass of the block (in kg) is : (taken $\mathrm{g}=10 \mathrm{~m} / \mathrm{s}^{2}$ ) $2.0$$4.0$$1.6$$2.5$Correct Option: 1 Solution:...
Read More →When monochromatic red light is used instead of blue light in a convex lens,
Question: When monochromatic red light is used instead of blue light in a convex lens, its focal length will:Does not depend on colour of light IncreaseDecreaseRemain sameCorrect Option: , 2 Solution:...
Read More →Solve this following
Question: A marble block of mass $2 \mathrm{~kg}$ lying on ice when given a velocity of $6 \mathrm{~m} / \mathrm{s}$ is stopped by friction in $10 \mathrm{~s}$. Then the coefficient of friction is- $0.02$$0.03$$0.06$$0.01$Correct Option: , 3 Solution:...
Read More →A body is thrown vertically
Question: A body is thrown vertically upwards. Which one of the following graphs correctly represent the velocity vs time ?Correct Option: 1 Solution:...
Read More →A car is fitted with a convex side-view mirror of focal length 20 cm.
Question: A car is fitted with a convex side-view mirror of focal length $20 \mathrm{~cm}$. A second car $2.8 \mathrm{~m}$ behind the first car is overtaking the first car at a relative speed of $15 \mathrm{~m} / \mathrm{s}$. The speed of the image of the second car as seen in the mirror of the first one is:- $10 \mathrm{~m} / \mathrm{s}$$15 \mathrm{~m} / \mathrm{s}$$\frac{1}{10} \mathrm{~m} / \mathrm{s}$$\frac{1}{15} \mathrm{~m} / \mathrm{s}$Correct Option: , 4 Solution:...
Read More →Two stones are thrown
Question: Two stones are thrown up simultaneously from the edge of a cliff $240 \mathrm{~m}$ high with initial speed of $10 \mathrm{~m} / \mathrm{s}$ and $40 \mathrm{~m} / \mathrm{s}$ respectively. Which of the following graph best represents the time variation of relative position of the second stone with respect to the first ? (Assume stones do not rebound after hitting the ground and neglect air resistance, take $\mathrm{g}=10 \mathrm{~m} / \mathrm{s}^{2}$ ) (The figure are schematic and not ...
Read More →A transparent solid cyclindrical rod has a refractive index of
Question: A transparent solid cyclindrical rod has a refractive index of $\frac{2}{\sqrt{3}}$. It is surrounded by air. A light ray is incident at the mid-point of one end of the rod as shown in the figure. The incident angle $\theta$ for which the light ray grazes along the wall of the rod is :- $\sin ^{-1}\left(\frac{2}{\sqrt{3}}\right)$$\sin ^{-1}\left(\frac{1}{\sqrt{3}}\right)$$\sin ^{-1}\left(\frac{1}{2}\right)$$\sin ^{-1}\left(\frac{\sqrt{3}}{2}\right)$Correct Option: , 2 Solution:...
Read More →Solve this following
Question: A horizontal force of $10 \mathrm{~N}$ is necessary to just hold a block stationary against a wall. The coefficient of friction between the block and the wall is $0.2$. The weight of the block is- $20 \mathrm{~N}$$50 \mathrm{~N}$$100 \mathrm{~N}$$2 \mathrm{~N}$Correct Option: , 4 Solution:...
Read More →From a tower of height
Question: From a tower of height $\mathrm{H}$, a particle is thrown vertically upwards with a speed $u$. The time taken by the particle, to hit the ground, is $n$ times that taken by it to reach the highest point of its path. The relation between $\mathrm{H}, u$ and $\mathrm{n}$ is :$2 \mathrm{~g} \mathrm{H}=\mathrm{nu}^{2}(\mathrm{n}-2)$$\mathrm{g} \mathrm{H}=(\mathrm{n}-2) \mathrm{u}^{2}$$2 \mathrm{~g} \mathrm{H}=\mathrm{n}^{2} \mathrm{u}^{2}$$\mathrm{g} \mathrm{H}=(\mathrm{n}-2)^{2} \mathrm{u...
Read More →An object, moving with
Question: An object, moving with a speed of $6.25 \mathrm{~m} / \mathrm{s}$, is decelerated at a rate given by $\frac{\mathrm{dv}}{\mathrm{dt}}=-2.5 \sqrt{\mathrm{v}}$ where $v$ is the instantaneous speed. The time taken by the object, to come to rest, would be :-$4 \mathrm{~s}$$8 \mathrm{~s}$$1 \mathrm{~s}$$2 \mathrm{~s}$Correct Option: , 4 Solution:...
Read More →In which of the following arrangements, the sequence is not strictly according to the property
Question: In which of the following arrangements, the sequence is not strictly according to the property written against it ? $\mathrm{CO}_{2}\mathrm{SiO}_{2}\mathrm{SnO}_{2}\mathrm{PbO}_{2}$ : increasing oxidising power$\mathrm{B}\mathrm{C}\mathrm{O}\mathrm{N}$ : increasing first ionisation enthalpy$\mathrm{NH}_{3}\mathrm{PH}_{3}\mathrm{AsH}_{3}\mathrm{SbH}_{3}$ : increasing basic strength$\mathrm{HF}\mathrm{HCl}\mathrm{HBr}\mathrm{HI}$ : increasing acid strengthCorrect Option: , 3 Solution:...
Read More →Consider the reaction
Question: Consider the reaction $\mathrm{H}_{2} \mathrm{SO}_{3(a q)}+\mathrm{S}_{(a \mathrm{aq})}^{4+}+\mathrm{H}_{2} \mathrm{O}_{(1)} \rightarrow \mathrm{S}_{(a q)}^{2+}+\mathrm{HSO}_{4(a q)}^{-}+3 \mathrm{H}_{\text {(aq) }}^{+}$ Which of the following statements is correct?$\mathrm{H}_{2} \mathrm{SO}_{3}$ is the reducing agent because it undergoes oxidation$\mathrm{H}_{2} \mathrm{SO}_{3}$ is the reducing agent because it undergoes reduction$\mathrm{Sn}^{4+}$ is the reducing agent because it un...
Read More →Which one of the following depletes ozone layer ?
Question: Which one of the following depletes ozone layer?NO and freons$\mathrm{SO}_{2}$$\mathrm{CO}$$\mathrm{CO}_{2}$Correct Option: 1 Solution: Solution not required...
Read More →Consider the reaction
Question: Consider the reaction $\mathrm{H}_{2} \mathrm{SO}_{3(a q)}+\mathrm{S}_{(a \mathrm{aq})}^{4+}+\mathrm{H}_{2} \mathrm{O}_{(1)} \rightarrow \mathrm{S}_{(a q)}^{2+}+\mathrm{HSO}_{4(a q)}^{-}+3 \mathrm{H}_{\text {(aq) }}^{+}$ Which of the following statements is correct?$\mathrm{H}_{2} \mathrm{SO}_{3}$ is the reducing agent because it undergoes oxidation $\mathrm{H}_{2} \mathrm{SO}_{3}$ is the reducing agent because it undergoes reduction$\mathrm{Sn}^{4+}$ is the reducing agent because it u...
Read More →Consider the reaction
Question: Consider the reaction $$ \mathrm{H}_{2} \mathrm{SO}_{3(\text { aq) }}+\mathrm{Sn}_{(a,)}^{4+}+\mathrm{H}_{2} \mathrm{O}_{(1)} \rightarrow \mathrm{Sn}_{(a q)}^{2+}+\mathrm{HSO}_{4(\text { aq })}^{-}+3 \mathrm{H}_{\text {(aq) }}^{+} $$ Which of the following statements is correct?$\mathrm{H}_{2} \mathrm{SO}_{3}$ is the reducing agent because it undergoes oxidation $\mathrm{H}_{2} \mathrm{SO}_{3}$ is the reducing agent because it undergoes reduction$\mathrm{Sn}^{4+}$ is the reducing agent...
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