One conducting U tube can slide inside another as shown in figure, maintaining electrical contacts between the tubes. The magnetic field B is perpendicular to the plane of the figure. If each tube moves towards the other at a constant sped v then the emf induced in the circuit in terms of B, l and v where l is the width of each tube, will be
|
(a) Zero |
(b) 2 Blv |
(c) Blv |
(d) -Blv |
(b) 2 Blv
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Laser beams are used to measure long distance because
|
(a) They are monochromatic |
(b) They are highly polarised |
|
(c) They are coherent |
(d) They have high degree of parallelism |
The figure below shows currents in a part of electric circuit. The current i is
|
(a) 1.7 amp |
(b) 3.7 amp |
(c) 1.3 amp |
(d) 1 amp |
A transparent cube of 15 cm edge contains a small air bubble. Its apparent depth when viewed through one face is 6 cm and when viewed through the opposite face is 4 cm. Then the refractive index of the material of the cube is
|
(a) 2.0 |
(b) 2.5 |
(c) 1.6 |
(d) 1.5 |
A proton of mass 1.67 
and charge 1.6 
is projected with a speed of 2 
m/s at an angle of 60° to the X - axis. If a uniform magnetic field of 0.104 Tesla is applied along Y - axis, the path of proton is
|
(a) A circle of radius = 0.2 m and time period |
|
(b) A circle of radius = 0.1 m and time period 2 |
|
(c) A helix of radius = 0.1 m and time period 2 |
|
(d) A helix of radius = 0.2 m and time period 4 |
The magnetic induction in the region between the pole faces of an electromagnet is 0.7 weber/m2. The induced e.m.f. in a straight conductor 10 cm long, perpendicular to B and moving perpendicular both to magnetic induction and its own length with a velocity 2 m/sec is
|
(a) 0.08 V |
(b) 0.14 V |
(c) 0.35 V |
(d) 0.07 V |
