A current carrying rectangular coil is placed in a uniform magnetic field. In which orientation, the coil will not tend to rotate
|
(a) The magnetic field is parallel to the plane of the coil |
|
(b) The magnetic field is perpendicular to the plane of the coil |
|
(c) The magnetic field is at 45o with the plane of the coil |
|
(d) Always in any orientation |
(b) The magnetic field is perpendicular to the plane of the coil
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
In a transistor, a change of 8.0 mA in the emitter current produces a change of 7.8 mA in the collector current. What change in the base current is necessary to produce the same change in the collector current
| (a) 50 mA | (b) 100 mA | (c) 150 mA | (d) 200 mA |
A potential difference of 2V is applied between the opposite faces of a Ge crystal plate of area 1 cm2 and thickness 0.5 mm. If the concentration of electrons in Ge is 2 × 1019/m3 and mobilities of electrons and holes are 0.36 
and 0.14 respectively, then the current flowing through the plate will be
|
(a) 0.25 A |
(b) 0.45 A |
(c) 0.56 A |
(d) 0.64 A |
There is 10 units of charge at the centre of a circle of radius 10m. The work done in moving 1 unit of charge around the circle once is
|
(a) Zero |
(b) 10 units |
(c) 100 units |
(d) 1 unit |
A long solenoid has a radius a and number of turns per unit length is n. If it carries a current i, then the magnetic field on its axis is directly proportional to
|
(a) ani |
(b) ni |
(c) |
(d) |
