Advertisements
Advertisements
प्रश्न
Modulus of rigidity of ideal liquids is ______.
विकल्प
infinity.
zero.
unity.
some finite small non-zero constant value.
उत्तर
Modulus of rigidity of ideal liquids is zero.
Explanation:
Modulus of Rigidity: Within limits of proportionality, the ratio of tangential stress to the shearing strain is called the modulus of rigidity of the material of the body and is denoted by η
i.e. η = `"Shearing stress"/"Shearing strain"`
In this case, the shape of a body changes but its volume remains unchanged.
Consider a cube of material fixed at its lower face and acted upon by a tangential force F at its upper surface having area A.
Only solids can exhibit a shearing as these have a definite shape.
In liquids, η = 0
So, the frictional (viscous) force cannot exist in the case of an ideal fluid and since they cannot sustain shearing stress or tangential forces are zero, there is no stress developed.
APPEARS IN
संबंधित प्रश्न
Determine the volume contraction of a solid copper cube, 10 cm on an edge, when subjected to a hydraulic pressure of 7.0 ×106 Pa.
When a block a mass M is suspended by a long wire of length L, the elastic potential potential energy stored in the wire is `1/2` × stress × strain × volume. Show that it is equal to `1/2` Mgl, where l is the extension. The loss in gravitational potential energy of the mass earth system is Mgl. Where does the remaining `1/2` Mgl energy go ?
A steel blade placed gently on the surface of water floats on it. If the same blade is kept well inside the water, it sinks. Explain.
A wire can sustain the weight of 20 kg before breaking. If the wire is cut into two equal parts, each part can sustain a weight of
Answer in one sentence.
Define strain.
A charged particle is moving in a uniform magnetic field in a circular path of radius R. When the energy of the particle becomes three times the original, the new radius will be ______.
Consider a long steel bar under a tensile stress due to forces F acting at the edges along the length of the bar (Figure). Consider a plane making an angle θ with the length. What are the tensile and shearing stresses on this plane
- For what angle is the tensile stress a maximum?
- For what angle is the shearing stress a maximum?
The value of tension in a long thin metal wire has been changed from T1 to T2. The lengths of the metal wire at two different values of tension T1 and T2 are l1 and l2 respectively. The actual length of the metal wire is ______.
If 'S' is stress and 'Y' is young's modulus of the material of a wire, the energy stored in the wire per unit volume is ______.
What is an elastomer?
