When a wire of length 10 m is subjected to a force of 100 N along its length, the lateral strain produced is 0.01 x 10-3 m. The Poisson's ratio was found to be 0.4. if the area of cross-section of wire is 0.025 m2, its Young's modulus is
A. 1.6 x 108 N/m2
B. 2.5 x 1010 N/m2
C. 1.25 x 1011 N/m2
D. 16 x 109 N/m2
A beam of charged particles of charge 'q' and mass m are accelerated from rest through a potential difference of 100 volts. They pass through crossed electric and magnetic fields which together produce null deflection. If these electronic and magnetic fields are respectively 15xl03 volts/m and 5weber/m2, then 'q/m' has a value, in coulomb/kg, equal to :
A. 9 x 104
B. 15
C. 4.5 x 104
D. 4.5 x 102
A tension of 22 N is applied to a copper wire of cross-sectional area 0.02 cm2 Young’s modulus of copper is 1.1x1011 N/m2and Poisson’s ratio 0.32. The decrease in cross sectional area will be
A. 1.28x10-6cm2
B. 1.6 x10-6cm2
C. 2.56 x10-6cm2
D. 0.64 x10-6cm2
A steel wire can withstand a load up to 2940 N, A load of 150 kg, is suspended from a rigid support. The maximum angle through which the wire can be displaced from the mean position, so that the wire does not break when the load passes through the position of equilibrium, is
A. 30o
B. 60o
C. 80o
D. 85o
The Poisson's ratio of a material is 0.4. If a force is applied to a wire of this material, there is a decrease of cross-sectional area by 2%. The percentage increase in its length is:
A. 3%
B. 2.5%
C. 1%
D. 0.5%
A wire stretches by 0.01 m when it is stretched by a certain force.Another wire of the same material but double the length and double the diameter is stretched by the same force.The elongation is
A. 0.005 m
B. 0.01 m
C. 0.02 m
D. 0.04 m
When a uniform wire of radius r, is stretched by a 2 kg weight the increase in its length is 2.00 mm. If the radius of the wire is r/2 and other conditions remaining the same, the increase in its length is
A. 2.00 mm
B. 4.00 mm
C. 6.00 mm
D. 8.00 mm
Which of the following is more effective in inducing nuclear fission ?
A. Fast neutron
B. Fast proton
C. Slow proton
D. Slow neutron
A light of length 75 cm is suspended from the ceiling horizontally by means of two vertical wires of equal length tied to its ends. One of the wires is made of steel of cross section 0.2 sq cm.The Position along the rod at which a weight may be hung to produce equal stresses.ysteel=20x1010 N/m2,Ybrass=10x1010N/m2
A. 50 cm from steel wire
B. 25 cm from steel wire
C. 33.3 cm from steel wire
D. 13.3 cm from steel wire
The length of an elastic string is 'a' metres when the longitudinal tension is 4 N and 'b' meters when the longitudinal tension is 5 N. The length of the string in metres when the longitudinal tension is 9 N is:
A. a - b
B. 5b - 4a
C. 2b - (1/4)a
D. 4a - 3b