Let L be the length and d be the diameter of cross- section of a wire. Wires of the same material with different L and d are subjected to the same tension along the length of the wire. In which of the following cases, the extension of wire will be the maximum ?
L = 200 cm, d = 0.5 mm
L = 300 cm, d = 1.0 mm
L = 50 cm, d = 0.05 mm
L = 100 cm, d = 0.2 mm
22320 cal of heat is supplied to 100 g of ice at O°C. If the latent heat of fusion of ice is 80 cal g-1 and latent heat of vaporization ofwater is 540 cal g-1, the final amount of water thus obtained and its temperature respectively are
8 g, 100°C
100 g, 90°C
92 g, 100°C
82 g, 100°C
A progressive wave moving along x-axis is represented by . The wavelength (λ) at which the maximum particle velocity is 3 times the wave velocity is
A/3
2A/(3π)
(2/3) πA
The magnetic flux linked with a coil satisfies the relation Wb, where t is the time in second. The emf induced in the coil at t = 2 s is
22 V
18 V
16 V
40 V
A charge +q is placed at the origin O of x-y axes as shown in the figure. The work done in taking a charge Q from A to B along the straight line AB is
What current will flow through the 2 k Ω resistor in the circuit shown in the figure ?
3 mA
6 mA
12 mA
36 mA
In a region, the intensity of an electric field is given by E = 2i + 3j+ k in Nc-1. The electric flux through a surface S = 1Oi m2 in the region is
5 Nm2C-1
10 Nm2C-1
15 Nm2C-1
20 Nm2C-1
A straight wire of length 2 m carries a current of 10 A. If this wire is placed in a uniform magnetic field of 0.15 T making an angle of 45° with the magnetic field, the applied force on the wire will be
1.5 N
3 N
Two elements A and B with atomic numbers ZA and ZB are used to produce characteristic X-rays with frequencies vA and vB respectively. If ZA : ZB = 1 : 2, then vA : vB will be
1 : 8
4 : 1
1 : 4
Two infinite parallel metal planes, contain electric charges with charge densities +σ and -σ respectively and they are separated by a small distance in air. If the permittivity of air is ε0,then the magnitude of the field between the two planes with its direction will be
σ/ε0 towards the positively charged plane
σ/ε0 towards the negatively charged plane
σ/(2ε0) towards the positively charged plane
0 and towards any direction
B.
σ/ε0 towards the negatively charged plane