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This section includes InterviewSolutions, each offering curated multiple-choice questions to sharpen your knowledge and support exam preparation. Choose a topic below to get started.
101. |
If the container filled with liquid gets accelerated horizontally or vertically, pressure in liquid gets changed. In liquid (`a_(y)`) for calculation of pressure, effective `g` is used. A closed box horizontal base `6 m` by `6 m` and a height `2m` is half filled with liquid. It is given a constant horizontal acceleration `g//2` and vertical downward acceleration `g//2`.The angle of the free surface with the horizontal is equal toA. `30^(@)`B. `tan^(-1)((2)/(3))`C. `tan^(-1)((1)/(3))`D. `45^(@)` |
Answer» Correct Answer - D | |
102. |
If the container filled with liquid gets accelerated horizontally or vertically, pressure in liquid gets changed. In liquid (`a_(y)`) for calculation of pressure, effective `g` is used. A closed box horizontal base `6 m` by `6 m` and a height `2m` is half filled with liquid. It is given a constant horizontal acceleration `g//2` and vertical downward acceleration `g//2`.What is the value of vertical acceleration of box for given horizontal acceleration `(g//2)`, so that no part of the bottom of the box is exposed?A. `(g)/(2)` upwardB. `(g)/(4)` downwardC. `(g)/(4)` upwardD. not possible. |
Answer» Correct Answer - A | |
103. |
One end of uniform wire of length L and of weight W is attached rigidly to a point in the roof and a weight N is suspended from its lower end if s is the area of cross-section of the wire the stress in the wire at a height `(L)/(4)` from its lower end isA. `(W_(1))/(s)`B. `([W_(1)+(W)/(4)])/(s)`C. `([W_(1)+(3W)/(4)])/(s)`D. `(W_(1)+W)/(4)` |
Answer» Correct Answer - B | |
104. |
The cylindrical tube of a spray pump has radius `R`, one end of which has `n` fine holes, each of radius `r`. If the speed of the liquid in the tube is `V`, the speed of the ejection of the liquid through the holes is:A. `(v)/(n)[(R)/(r)]`B. `(v)/(n)[(R)/(r)]^((1)/(2))`C. `(v)/(n)[(R)/(r)]^((3)/(2))`D. `(v)/(n)[(R)/(r)]^(2)` |
Answer» Correct Answer - D | |
105. |
There are two identical small holes on the opposite sides of a tank containing a liquid. The tank is open at the top. The difference in height between the two holes is `h`. As the liquid comes out of the two holes. The tank will experience a net horizontal force proportional to. .A. `sqrt(h)`B. `h`C. `h^(3//2)`D. `h^(2)` |
Answer» Correct Answer - B | |
106. |
Two spheres P and Q of equal radii have densities `rho_1` and `rho_2`, respectively. The spheres are connected by a massless string and placed in liquids `L_1` and `L_2` of densities `sigma_1` and `sigma_2` and viscosities `eta_1` and `eta_2`, respectively. They float in equilibrium with the sphere P in `L_1` and sphere Q in `L_2` and the string being taut(see figure). If sphere P alone in `L_2` has terminal velocity `vecV_p` and Q alone in `L_1` has terminal velocity `vecV_Q`, then A. `(|vec(V)_(P)|)/(|vec(V)_(Q)|)=(eta_(1))/(eta_(2))`B. `(|vec(V)_(P)|)/(|vec(V)_(Q)|)=(eta_(2))/(eta_(1))`C. `vec(V)_(P).vec(V)_(Q)gt0`D. `vec(V)_(P).vec(V)P_(Q)lt0` |
Answer» Correct Answer - A::D | |
107. |
A jar is filled with two non-mixing liquids 1 and 2 haivng densities `rho_1` and `rho_2` respectively. A solid ball, made of a material of density `rho_3` , is dropped in the jar. It comes to equilibrium in the position shown in the figure. Which of the following is true for `rho_1`, `rho_1` and `rho_3`? A. `rho_(3)ltrho_(1)ltrho_(2)`B. `rho_(1)gtrho_(3)gtrho_(2)`C. `rho_(1)ltrho_(2)ltrho_(3)`D. `rho_(1)ltrho_(3)ltrho_(2)` |
Answer» Correct Answer - D | |
108. |
A uniform solid cylinder of density `0.8g//cm^3` floats in equilibrium in a combination of two non-mixing liquids A and B with its axis vertical. The densities of the liquids A and B are `0.7g//cm^3` and `1.2g//cm^3`, respectively. The height of liquid A is `h_A=1.2cm.` The length of the part of the cylinder immersed in liquid B is `h_B=0.8cm`. (a) Find the total force exerted by liquid A on the cylinder. (b) Find h, the length of the part of the cylinder in air. (c) The cylinder is depressed in such a way that its top surface is just below the upper surface of liquid A and is then released. Find the acceleration of the cylinder immediately after it is released. |
Answer» Correct Answer - (i). Zero (ii). 0.25 m (iii). `(g)/(6)` |
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109. |
A solid uniform ball having volume V and density `rho` floats at the interface of two unmixible liquids as shown in Fig. 7(CF).7. The densities of the upper and lower liquids are `rho_(1)` and `rho_(2)` respectively, such that `rho_(1) lt rho lt rho_(2)`. What fractio9n of the volume of the ball will be in the lower liquid. A. `(rho-rho_(2))/(rho_(1)-rho_(2))`B. `(rho_(1))/(rho_(1)-rho_(2))`C. `(rho_(1)-rho)/(rho_(1)-rho_(2))`D. `(rho_(1)-rho_(2))/(rho_(2))` |
Answer» Correct Answer - C | |
110. |
A small uniform tube is bent into a circle of radius r whose plane is vertical. Equal volumes of two fluids whose densities are`rho` and `sigma(rhogtsigma)` fill half the circle. Find the angle that the radius passing through the interface makes with the vertical. A. `theta=tan^(-1)((rho-sigma)/(rho+sigma))`B. `theta=tan^(-1)((sigma-rho)/(sigma+rho))`C. `theta=tan^(-1)((rho)/(rho+sigma))`D. `theta=tan^(-1)((rho)/(rho-sigma))` |
Answer» Correct Answer - A | |
111. |
A cylinderical container of length L is full to the brim with a liquid which has mass density `rho`. It is placed on a weight scale, the scale reading is w. A light wall ball which would float on the liquid if allowed to do so, of volume V and mass m is pushed gently down and held beneath the surface of the liquid with a rigid rod of negligible volume as shown on the left Q. What is the reading of the scale when the ball is fully immersed (a). `w-rhoVg` (b). w (c). `w+mg-rhoVg` (d). none of these |
Answer» Correct Answer - C Weight mg is entered while weight `rhoVg` of liquid is overflowed. |
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112. |
Water is filled in a cylindrical container to a height of `3m`. The ratio of the cross-sectional area of the orifice and the beaker is `0.1`. The square of the speed of the liquid coming out from the orifice is `(g=10m//s^(2))`. A. `50m^(2)s^(2)`B. `50.5m^(2)s^(2)`C. `51m^(2)s^(2)`D. `52m^(2)s^(2)` |
Answer» Correct Answer - A | |
113. |
The vessel shown in the figure has a two sections of areas of cross-section `A_1` and `A_2`. A liquid of density `rho` fills both th sections, up to a height `h` in each Neglect atmospheric pressure. Choose the wrong option. .A. The pressure at the base of the vessel is `2hrhog`B. The force exerted by the liquid on the base of the vessel is `2hrhogA_(2)`C. The weight of the liquid is `lt2hrhogA_(2)`D. The walls of the vessel at the level X exert a downward force `hrhog(A_(2)-A_(1))` on the liquid. |
Answer» Correct Answer - A::B::C::D | |
114. |
A vessel contains two immiscible liquids of density `rho_(1)=1000 kg//m^(3)` and `rho_(2)=1500kg//m^(3)`. A solid block of volume `V=10^(3)m^(3)` and density `d=800kg//m^(3)` is tied to one end of a string and the outer end is tied to the bottom of the vessel as shown in figure. The block is immersed with two fifths of its volume in the liquid of lower density. The entire system is kept in an elevator which is moving upwards with an acceleration of `a=g/2`. Find the tension in the string. |
Answer» Correct Answer - `6N` | |
115. |
A container of large uniform cross-sectional area A resting on a horizontal surface, holes two immiscible, non-viscon and incompressible liquids of densities d and 2d each of height `H//2` as shown in the figure. The lower density liquid is open to the atmosphere having pressure `P_(0)`. A homogeneous solid cylinder of length `L(LltH//2)` and cross-sectional area `A//5` is immeresed such that it floats with its axis vertical at the liquid-liquid interface with length `L//4` in the denser liquid, The cylinder is then removed and the original arrangement is restroed. a tiny hole of area `s(sltltA)` is punched on the vertical side of the container at a height `h(hltH//2)`. As a result of this, liquid starts flowing out of the hole with a range x on the horizontal surface. The total pressure with cylinder, at the bottom of the container is |
Answer» Correct Answer - (i). (a). `D=(5)/(4)d` (b). `P=P_(0)+(1)/(4)(6H+L)dg` (ii). (a). `v=sqrt((g)/(2)(3H-4h))` (b). `x=sqrt(h(3H-4h))` (c). `x_(max)=(3)/(4)H` |
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116. |
A square box of water has a small hole located the bottom corners. When the box is full and sitting on a level surface, complete opening of the hole results in a flow of water with a speed `v_(0)` as shown in Fig. (a). when the box is still half empty, it is tilted by `45^@` so that hole is at the lowest point. Now the water will flow out with a speed of A. `v_(0)`B. `(v_(0))/(2)`C. `(v_(0))/(sqrt(2))`D. `(v_(0))/(root(4)(2))` |
Answer» Correct Answer - D | |
117. |
A cylinderical tank 1 m in radius rests on a plaform 5 m high. Initially the tank is filled with upto a height of 5m a plug whose area is `10^(-4)cm^(2)` is removed from an orifice on the side of the tank at the bottom. Calculate (a). Initial speed with which the water flows from the orifice (b). Initial speed with which the water strikes the ground. |
Answer» (a). Speed of efflux `V_(H)=sqrt((2gh))=sqrt(2xx10xx5)=10m//s` (b). As initial vertical velocity of water is zero, so its verticalj velocity when it hits the ground `V_(V)=sqrt(2gh)=sqrt(2xx10xx5)=10m//s` So the initial speed with which water strikes the group, `V=sqrt(V_(H)^(2)+V_(V)^(2))=10sqrt(2)=14.1m//s` |
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118. |
In a movable container shown in figure a liquid of density `rho` is filled up to a height h the upper & lower the cross sectional areas are `A_(2)&A_(1)` respectively `(A_(2)gtgtA_(1))` if the liquid leaves out the container through the tube of cross-sectional area `A_(1)` then find. (i). Velocity of liquid coming out. (ii). Backward acceleration of the container. |
Answer» Correct Answer - (i). `v=(sqrt(2gh)), (ii). `a=(2gA_(1))/(A_(2))` | |
119. |
A cylinderical tank having cross sectional area `^^=0.5m^(2)` is filled liquids of densities `rho_(1)=900kgm^(3)&rho_(2)=600kgm^(3)` to a height `h=60cm` as shown in the figure a small hole having area `a=5cm^(2)` is made in right vertical wall at a height `y=20cm` from the bottom calculate. (i). velocity of efflux (ii). horizontal force F to keep the cylinder in static equilibrium if it is placed on a smooth horizontal plane (iii). minimum and maximum value of F to keep the cylinder at rest. The coefficient of friction between cylinder and the plane is `mu=0.1` (iv). velocity of the top most layer of the liquid column and also the velocity of the boundary separating the two liquids. |
Answer» Correct Answer - (i). `4m//s` (ii). `F=7.2N` (iii). `F_(min)=0,F_(max)=52.2N` (iv). Both `4xx10^(-3)m//s` |
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120. |
A large open top container of negligible mass and uniform cross sectional area `A` a has a small hole of cross sectional area `A//100` in its side wall near the bottom. The container is kept on a smooth horizontal floor and contains a liquid of density `rho` and mass `M_(0)`. Assuming that the liquid starts flowing out horizontally through the hole at `t=0`, calculate a the acceleration of the container and b its velocity when `75%` of the liquid has drained out. |
Answer» Correct Answer - (i). 0.2`m//s^(2)` (ii). `sqrt(2g(m_(0))/(Arho))` |
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121. |
A tank full of water has a small hole at its bottom. Let `t_(1)` be the time taken to empty first one third of the tank and `t_(2)` be the time taken to empty second one third of the tank and `t_(3)` be the time taken to empty rest of the tank then (a). `t_(1)=t_(2)=t_(3)` (b). `t_(1)gtt_(2)gtt_(3)` (c). `t_(1)ltt_(2)ltt_(3)` (d). `t_(1)gtt_(2)ltt_(3)` |
Answer» Correct Answer - C As the height decreases, the rate of flow with which the water is coming out decreases. |
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122. |
A large cylinderical tank of cross-sectional area `1m^(2)` is filled with water . It has a small hole at a height of 1 m from the bottom. A movable piston of mass 5 kg is fitted on the top of the tank such that it can slide in the tank freely. A load of 45 kg is applied on the top of water by piston, as shown in figure. The value of v when piston is 7 m above the bottom is `(g=10m//s^(2)`) (a). `sqrt(120)m//s` (b). `10m//s` (c). `1m//s` (d). `11m//s` |
Answer» Correct Answer - D `(1)/(2)rhov^(2)=rhogh+(Mg)/(A)impliesV=sqrt(2gh+(2Mg)/(rhoA))=sqrt(2xx10xx6+(2xx50xx10)/(10^(3)xx1))=sqrt(120+1)=sqrt(121)=11m//s` |
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123. |
The water level on a tank is 5m high. There is a hole of `1 cm^(2)` cross-section at the bottom of the tank. Find the initial rate with which water will leak through the hole. (`g= 10ms^(-2)`)A. `10^(-3)m^(3)//s`B. `10^(-4)m^(3)//s`C. `10m^(3)//s`D. `10^(-2)m^(3)//s` |
Answer» Correct Answer - A | |
124. |
A wooden plank of length 1m and uniform cross-section is hinged at one end to the bottom of a tank as shown in fig. The tank is filled with water upto a hight 0.5m. The specific gravity of the plank is 0.5. Find the angle `theta` that the plank makes with the vertical in the equilibrium position. (Exclude the case `theta=theta^@`) |
Answer» Correct Answer - `45^(@)` | |
125. |
A hole is made at the bottom of a large vessel open at the top. If water is filled to a height h it drain out completely in time t. The time taken by the water column of height 2h to drain completely is (a). `sqrt(2t)` (b). `2t` (c). `2sqrt(2t)` (d). `4t` |
Answer» Correct Answer - A Here `(-A(dh)/(dt))=(av)=asqrt(2gh)impliesunderset(0)overset(h)intyh^(-1//2)d=(a)/(A)sqrt(2g)underset(0)overset(h)intdtimpliest=(A)/(a)sqrt((2h)/(g))impliestpropsqrt(h)` |
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126. |
A cylindrical vessel of height 500mm has an orifice (small hole) at its bottom. The orifice is initially closed and water is filled in it up to height H. Now the top is completely sealed with a cap and the orifice at the bottom is opened. Some water comes out from the orifice and the water level in the vessel becomes steady with height of water column being 200mm. Find the fall in height(in mm) of water level due to opening of the orifice. [Take atmospheric pressure `=1.0xx10^5N//m^2`, density of water=1000kg//m^3` and `g=10m//s^2`. Neglect any effect of surface tension.] |
Answer» Correct Answer - 206 | |
127. |
A tank is filled with a liquid upto a height H, A small hole is made at the bottom of this tank Let `t_(1)` be the time taken to empty first half of the tank and `t_(2)` time taken to empty rest half of the tank then find `(t_(1))/(t_(2))` |
Answer» Let at some instant of time the level of liquid in the tank is y. Velocity of efflux at this instant of time `v=sqrt(2gy)` Now, at this instant volume of liquid coming out the hole per second is `((dV_(1))/(dt))` Volume of liquid coming down in the tank per second is `((dV_(2))/(dt))` `(dV_(1))/(dt)=(dV_(2))/(dt)impliesav=A((-dy)/(dt))thereforeasqrt(2gy)=A(-(dy)/(dt))` ...(i) (Here area of cross-section of hole and tank are respectively a and A) Substituting the proper limits in equation (i). `int_(0)^(t_(1))dt=-(A)/(asqrt(2g))int_(H)^(H//2)y^(-1//2)dyimpliest_(1)=(2A)/(asqrt(2g))[sqrt(y)]_(H//2)^(H)=(2A)/(asqrt(2g))[sqrt(H)-sqrt((H)/(2))]=(A)/(a)sqrt((H)/(g))(sqrt(2)-1)` ....(ii) Similarly `int_(0)^(t_(2))dt=-(A)/(asqrt(2g))int_(H//2)^(0)y^(-1//2)dyimpliest_(2)=(A)/(a)sqrt((H)/(g))` ....(iii) From equation (ii) and (iii), `(t_(1))/(t_(2))=sqrt(2)-1=0.414` |
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128. |
Alight rod of length 2 m is suspended horizontlly from the ceiling bty means of two vertical wirs of equal length tied to its ends One wire is mode of steel and is of cross - section 0.1 sq cm and the other is of brass of cross -section 0.2 sq cm Find the postion along the rod at which a wight may be hung to produce (i) equal stress in both wirs (ii) equal strain in both wires (Y for brass `=10xx10^(10) Nm^(-2) and Y "for steel" =20xx10^(10) Nm^(-2)`) |
Answer» Correct Answer - `(i) 1.33m, (ii) 1m` |
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129. |
The height to which water rises in a capillary will beA. maximum at `4^(@)C`B. maximum at `0^(@)C`C. minimum at `0^(@)C`D. minimum at `4^(@)C` |
Answer» Correct Answer - D | |
130. |
In a capillary tube experiment, a vertical 30 cm long capillary tube is dipped in water. The water rises up to a height of 10 cm due to capillary action. If this experiment is conducted in a freely falling elevator, the length of te water column becomesA. 10 cmB. 20 cmC. 30 cmD. zero |
Answer» Correct Answer - C | |
131. |
Two wires having same length and material are stretched by same force. Their diameters are in the ratio 1:3. The ratio of strain energy per unit volume for these two wires (smaller to larger diameter) when stretched isA. `3 : 1`B. `9 : 1`C. `27 : 1`D. `81 : 1` |
Answer» Correct Answer - b According to question, energy in string per unit volume is given by `(1)/(2) xx` stress `xx` strain i.e., `(U)/(V) = (1)/(2) xx (F)/(A) xx (Delta l)/(l)` [Symbols have their usual meanings] `= (1)/(2) xx V xx ("strain")^(2)` `:. (U_(s))/(S_(L)) = (Y_(s))/(Y_(L)) xx ("Stress"(S))/("Strain"(L))^(2)` `= (A_(L))/(A_(S)) = ((l)/(l))^(2)` `implies (r_(L)^(2))/(r_(s)^(2)) = (3^(2))/(1^(2)) = 9 : 1` |
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132. |
A steel sprial spring has on unstreched length of 8cm and when a mass is hung o it, its length becomes 10cm. Calculate the periodic time of the oscillation that would occur if the masss were displaced vertically. |
Answer» Correct Answer - `(1)/(6)pi^(2)hdelta^(3) Y//l=80J` |
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133. |
A fixed volume of iron is drawn into a wire of length `l`. The extension produced in this wire by a constant force F is proportional toA. `(1)/(L^(2))`B. `(1)/(L)`C. `L^(2)`D. `L` |
Answer» Correct Answer - C |
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134. |
A cable that can support a load W is cut into two equal parts .T he maximum load that can be supported by either part isA. WB. W/2C. W/4D. 2W |
Answer» Correct Answer - A Breaking load depends upon radius but it is independent of length max stress = W. |
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135. |
The side of glass aquarium is 1 m high and 2m long, when the aquarium is filled to the top with water what is the total force against the side-A. `980xx10^(3)N`B. `9.8xx10^(3)N`C. `0.98xx10^(3)N`D. `0.098xx10^(3)N` |
Answer» Correct Answer - B | |
136. |
Calculate the value of stress on a wire of steel having radius of 2 mm, when 10 kN of force is applied on it.A. `7.76 xx 10^(8) Nm^(-2)`B. `7.96 xx 10^(8) Nm^(-2)`C. `6.96 xx 10^(8) Nm^(-2)`D. `5.56 xx 10^(8) Nm^(-2)` |
Answer» Given, force `F = 10 kN = 1 xx 10^(4) N` Radius, `r = 2 mm = 2 xx 10^(-3) m` Area, `A = pi r^(2) = pi xx (2 xx 10^(-3))^(2)` `= 12.56 xx 10^(-6) m^(2)` Stress `= ("Force")/("Area") = (1 xx 10^(4) N)/(12.56 xx 10^(-6) m^(2))` `= 0.0796 xx 10^(10)` Stress `= 7.96 xx 10^(8) Nm^(-2)` |
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137. |
A stell wire of 1m long `1mm^(2)` cross section area is hang from rigid end. The length of 1kg is hung from it then change in length will be (given `Y = 2 xx 10^(11) N//m^(2)`)A. 0.5 mmB. 0.25 mmC. 0.05 mmD. 5 mm |
Answer» Correct Answer - C |
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138. |
The lower surface of a cube is fixed. On its upper surface, force is applied at an angle of `30^@` from its surface. The change will be the typeA. ShapeB. SizeC. NoneD. Shape and size |
Answer» Correct Answer - D |
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139. |
The forces of `10^(6)` N each are applied on opposite directions on upper and lower faces of a cube of side 10 cm, shifting and lower faces of a cube of side 10 cm, shifting the upper face parallel to itself by 0.8 cm. If the side of the cube were 20 cm, Then the displacement of the cube will beA. 0.2 cmB. 0.8 cmC. 0.4 cmD. 0.6 cm |
Answer» Correct Answer - C `eta=(Fh_(1))/(A_(1)x_(1))=(Fh_(2))/(A_(2)x_(2)) " " therefore A_(1)x_(1)=A_(2)x_(2)` |
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140. |
The lower surface of a cube is fixed. On its upper surface, force is applied at an angle of `30^@` from its surface. The change will be the typeA. shapeB. sizeC. volumeD. Both shape and size |
Answer» Correct Answer - D (d) On stretching a spiral, both types of strains are produce, i.e., longitudinal and shear strain. |
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141. |
A rubber ball of mass 10 gram and volume `15 cm^3` is dipped in water to a depth of 10m. Assuming density of water uniform throughtout the depth, find (a) the ac celeration of the ball, and (b) the time taken by it to reach the surface if it is relased from rest. `(Take g =980 cm//s^2)` |
Answer» the maximum buoyant force on the ball is `F_(B)=Vrho_(w)g=15xx1xx980"dyne"=14700"dyne"` The weight of the ball is mg `=10xxg=10xx980=9800"dyne"` the net upward force `F=(15xx980-10xx980)"dyne"=5xx980"dyne"=4900"dyne"` (a). Therefore, acceleration of the ball upward `a=(F)/(m)=(5xx980)/(10)=490cm//s^(2)=4.9m//s^(2)` (b). Time taken by it reach the surface is `t=sqrt((2h)/(a))=sqrt((2xx10)/(4.9))s=2.02s` |
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142. |
Assertion Bulk modulus of an incompressible fluid is infinite. Reason Density of incompressible fluid remains constant.A. If both Assertion and Reason are true and Reason is the correct explanation of Assertion.B. If both Assertion and Reason are true but Reason is not the correct explanation of Assertion.C. If Assertion is true but Reason is false.D. If both Assertion and Reason are false. |
Answer» Correct Answer - B (b) Incompressible fluid is that which cannot be compressed `(DeltaV=0)` by applying pressure on it. |
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143. |
Water rises to a height of 20 mm in a capillary if the radius of the capillary is made one third of its previous value then what is the new value of the capillary rise? |
Answer» Since `h=(2Tcostheta)/(rdg)` and the same liquid and capillaries of difference radii `h_(1)r_(1)=h_(2)r_(2)` `therefore(h_(2))/(h_(1))=(r_(1))/(r_(2))=(1)/((1//3))=3` hence `h_(2)=3h_(1)=3xx20mm=60mm` |
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144. |
The strain energy per unit volume of a stretched wire isA. `1//2 xx ` stress `xx` strainB. `1//2 xx ("strain")^(2)xx Y`C. `1//2 xx ("stress")^(2)//Y`D. all of these |
Answer» Correct Answer - D | |
145. |
Substances which can be elastically stretched to large value of strain are calledA. IsomersB. IsodiapheresC. PlastomersD. Elastomers |
Answer» Correct Answer - D (d) Elastomers can be elastically stretched to large value of strain. |
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146. |
Assertion : steel is more elastic than rubber. Reason : For same strain , steel requires more stress to be produced in it.A. (a) If both Assertion and Reason are true and the Reason is correctn explanation of the Assertion.B. (b) If both Assertion and Reason are true but Reason is not the correct explanation of Assertion.C. If Assertion is true, but the Reason is false.D. If Assertion is false but the Reason is true. |
Answer» Correct Answer - A | |
147. |
Two liquids of densities `d_(1)` and `d_(2)` are flowing in identical capillaries under same pressure difference. If `t_(1)` and `t_(2)` are the time taken for the flow of equal quantities of liquid, then the ratio of coefficients of viscosities of liquids must beA. `(d_(1)d_(2))/(t_(1)t_(2))`B. `(d_(1)t_(1))/(d_(2)t_(2))`C. `(d_(1)t_(2))/(d_(2)t_(1))`D. `sqrt(((d_(1)t_(1))/(d_(2)t_(2))))` |
Answer» Correct Answer - B | |
148. |
Match the following column I and column II. `{:("Column I","Column II"),(A. "Stress" xx "strain", 1. j),(B. YA//I,2. N//m),(C.Yl^(3),3.J//m^(3)),(D.Fl//AY,4.m):}`A. 3,2,1,4B. 2,1,4,3C. 3,4,1,2D. 1,2,4,3 |
Answer» Correct Answer - a `A to 3, B to 2, C to 1, D to 4` `{:("column I","Column II")/(A."Stress"xx"strain",3.J//m^(3)),(B.((YA)/(I),2.N//m),(C.YI^(3),1.j),(D.FI//AY,4.m):}` |
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149. |
A substance breaks down by a stress of `10^(6) Nm^(-2)`. If the density of the material of the wire is `3 xx 10^(3) kgm^(-3)`. Then the length of the wire of the substance which will break under its own weight when suspended vertically isA. 66.6 mB. 60.0 mC. 33.3 mD. 30.9 m |
Answer» Correct Answer - c If an external force F is applied to the cross-sectional area A of the body, then stress `= (F)/(A) = (mg)/(A)` Where, Mass m = volume `xx` Density = Alp `:.` stress `= (Al rho g)/(A) = rho Lg` `:. L = ("Breaking stress")/(rho g)` Given, breaking stress `= 10^(6) Nm^(-2)` `rho = 3 xx 10^(3) kgm^(-3)` and `g = 10 ms^(-2)` `:. L = (10^(6))/((3 xx 10^(3)) xx 10) = 33.3 m` |
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150. |
If the breaking force for a given wire is F, then the breaking force of two wires of same magnitude will beA. FB. 4 FC. 8 FD. 2 F |
Answer» Correct Answer - D |
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