CBSE
A wire of length L and cross-sectional area A is made of a material of Young's modulus Y. It is stretched by an amount x. The work done is
The force of cohesion is
maximum in solids
maximum in liquids
maximum in gases
same in solid, liquid and gas
A steel scale measures the length of a copper wire as 80.0 cm when both are at 20°C, the calibration temperature for the scale. What would the scale read for the length of the wire when both are at 40°C?
Given : α for steel = 11 × 10-6 per °C and for Cu= 17 × 10-6 per °C :
80.0096 cm
80.0272
1 cm
25.2 cm
A 5m aluminium wire (Y = 7 × 1010 N/m2) of diameter 3mm supports a 40 kg mass. In order to have the same elongation in copper wire (Y =12 x 1010 N/m2) of the same length under the same weight, the diameter should be in mm :
1.75
2.0
2.3
5.0
The Young's modulus of a wire is numerically equal to the stress which will
not change the length of the wire
double the length of the wire
increase the length
change the radius of the wire to half
Minimum and maximum values of Poisson's ratio for a metal lies between:
- ∞ to + ∞
0 to 1
- ∞ to 1
0 to 0.5
The manifestation of band structure in solids is due to
Heisenberg's uncertainly principle
Pauli's exclusion principle
Bob's correspondence principle
Boltzmann's law
A wire of diameter 1 mm breaks under a tension of 1000 N. Another wire, of same material as that of the first one, but of diameter 2 mm, breaks under a tension of :
500 N
100 N
1000 N
4000 N
A 4 m long copper wire of cross-sectional area 1.2 cm2 is stretched by a force of 4.8 x 103 N. Young's modulus for copper is Y = 1.2 x 1011 N/m2, the increase in length of the wire is
1.32 mm
0.8 mm
0.48 mm
5.36 mm
A one-metre long steel wire of cross-sectional area 1mm2 is extended by 1 mm. If Y=2 x 1011 N/m2, then the work done is :
0.1 J
0.2 J
0.3 J
0.4 J