CBSE
Multiple Choice QuestionsWhen a force F is applied on a wire oflength L and radius r, extension produce is l. If same force F is applied on the same material wire of length 2 L and radius 2r, then extension will be
l
2l
l/2
4l
Energy stored in the unit volume of a wire due to its elasticity is
stress/strain
force/strain
Which of the following has maximum property of elasticity?
Rubber
Lead
Wood
Steel
Copper has face centred cubic (fcc) lattice with interatomic spacing equals to 2.54 . The value of lattice constant for this lattice is
3.59
2.54
1.27
5.08
A copper wire and a steel wire of the same diameter and length are connected end to end and a force is applied which stretches their combined length by 1 cm. Then the two wires will have
the same stress and strain
the same stress but different strain
the same strain but different stress
different stress and strain
A solid sphere of radius r made of a material of bulk modulus K is surrounded by a liquid in cyliridrical container. The massless piston of area A floats on the surface of the liquid. If a mass m is placed on a piston to compress the liquid, then the fractional change in the radius of the sphere will be
Two wires of same material and length are stretched by the same force. Their masses are in the ratio 4 : 3. The ratio of their elongation will be
16 : 9
9 : 16
4 : 3
3 : 4
A wire suspended vertically from one of its ends is stretched by attaching a weight 100 N to the lower end. The wire stretches by 1mm. The elastic energy stored in the wire is
0.02 J
0.05 J
0.1 J
0.2 J
A circular metal plate of radius 5 cm rests on a layer of centre oil 2mm thick whose coefficient of viscosity is 15.5 dyne cm-2 s. The value of shearing stress when a horizontal force move the plate with a speed of 5 cm/s will be
387.5 dyne cm-2
328 dyne cm-2
250 dyne cm-2
428 dyne cm-2
A steel wire of length 15 m has density = 7.7 × 103 kg/m3 and Young's modulus = 2.2 × 1011 N/m2. It is subjected to a tension which produces an elastic strain of 1%. Its fundamental frequency of vibration must be
256 Hz
178 Hz
170 Hz
200 Hz
