Assertion (A): | A needle placed carefully on the surface of the water may float, whereas a ball of the same material will always sink. |
Reason (R): | The buoyancy of an object depends both on the material and shape of the object. |
1. | Both (A) and (R) are true and (R) is the correct explanation of (A). |
2. | Both (A) and (R) are true but (R) is not the correct explanation of (A). |
3. | (A) is true but (R) is false. |
4. | Both (A) and (R) are false. |
Assertion (A): | The shape of an automobile is so designed that its front resembles the streamlined pattern of the fluid through which it moves. |
Reason (R): | The resistance offered by the fluid is maximum. |
1. | Both (A) and (R) are true and (R) is the correct explanation of (A). |
2. | Both (A) and (R) are true but (R) is not the correct explanation of (A). |
3. | (A) is true but (R) is false. |
4. | Both (A) and (R) are false. |
Assertion (A): | If the speed of a fluid element increases as it travels along a horizontal streamline, the viscosity of the fluid must decrease. |
Reason (R): | Bernoulli's equation is applicable for all types of fluid flow. |
1. | Both (A) and (R) are true and (R) is the correct explanation of (A). |
2. | Both (A) and (R) are true but (R) is not the correct explanation of (A). |
3. | (A) is true but (R) is false. |
4. | Both (A) and (R) are false. |
Assertion (A): | Machine parts often become jammed in winter. |
Reason (R): | The viscosity of lubricants used in machine parts increases at low temperatures. |
1. | Both (A) and (R) are True and (R) is the correct explanation of (A). |
2. | Both (A) and (R) are True but (R) is not the correct explanation of (A). |
3. | (A) is True but (R) is False. |
4. | Both (A) and (R) are False. |
Assertion (A): | A hydrogen-filled balloon stops rising after it has attained a certain height in the sky. |
Reason (R): | The atmospheric pressure decreases with height and becomes zero when maximum height is attained. |
1. | Both (A) and (R) are true and (R) is the correct explanation of (A). |
2. | Both (A) and (R) are true but (R) is not the correct explanation of (A). |
3. | (A) is true but (R) is false. |
4. | Both (A) and (R) are false. |
Assertion (A): | When a capillary tube is dipped into mercury, the mercury level in the tube falls. |
Reason (R): | Mercury is a very viscous liquid. |
1. | Both (A) and (R) are true and (R) is the correct explanation of (A). |
2. | Both (A) and (R) are true but (R) is not the correct explanation of (A). |
3. | (A) is true but (R) is false. |
4. | Both (A) and (R) are false. |
Assertion (A): | Specific gravity of a fluid is a dimensionless quantity. |
Reason (R): | It is the ratio of the density of the fluid to the density of water. |
1. | Both (A) and (R) are True and (R) is the correct explanation of (A). |
2. | Both (A) and (R) are True but (R) is not the correct explanation of (A). |
3. | (A) is True but (R) is False. |
4. | Both (A) and (R) are False. |
Assertion (A): | For Reynold number \(R_{e}>3000,\) the flow of fluid is turbulent. |
Reason (R): | Inertial forces are dominant compared to viscous forces at such high Reynold's numbers. |
1. | Both (A) and (R) are true and (R) is the correct explanation of (A). |
2. | Both (A) and (R) are true but (R) is not the correct explanation of (A). |
3. | (A) is true but (R) is false. |
4. | Both (A) and (R) are false. |
Assertion (A): | The equation of continuity is \(A_{1}v_{1}\rho_1=\)\(A_{2}v_{2}\rho_2\) (symbols have their usual meanings). |
Reason (R): | The equation of continuity is valid only for incompressible liquids. |
1. | Both (A) and (R) are true and (R) is the correct explanation of (A). |
2. | Both (A) and (R) are true but (R) is not the correct explanation of (A). |
3. | (A) is true but (R) is false. |
4. | Both (A) and (R) are false. |
Assertion (A): | Atomizer is based on the principle of Bernoulli's theorem. |
Reason (R): | Bernoulli's theorem is based on the conservation of energy. |
1. | Both (A) and (R) are true and (R) is the correct explanation of (A). |
2. | Both (A) and (R) are true but (R) is not the correct explanation of (A). |
3. | (A) is true but (R) is false. |
4. | Both (A) and (R) are false. |