The electric intensity E, current density j and specific resistance k are related to each other by the relation
|
(a) E = j/k |
(b) E = jk |
(c) E = k/j |
(d) k = jE |
(b) E = jk
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
According to Bohr's theory, the expressions for the kinetic and potential energy of an electron revolving in an orbit is given respectively by
|
(a) + |
(b) + |
|
(c) |
(d) + |
A conductor of 3 m in length is moving perpendicularly to magnetic field of 
tesla with the speed of 
, then the e.m.f. produced across the ends of conductor will be
|
(a) 0.03 volt |
(b) 0.3 volt |
(c) 3 × |
(d) 3 volt |
The capacity of a parallel plate condenser is 10 μF, when the distance between its plates is 8 cm. If the distance between the plates is reduced to 4 cm, then the capacity of this parallel plate condenser will be
|
(a) 5 μF |
(b) 10 μF |
(c) 20 μF |
(d) 40 μF |
A wire in the form of a square of side ‘a’ carries a current i. Then the magnetic induction at the centre of the square wire is (Magnetic permeability of free space = 
|
(a) |
(b) |
(c) |
(d) |
The resistance of a wire is 20 ohms. It is so stretched that the length becomes three times, then the new resistance of the wire will be
|
(a) 6.67 ohms |
(b) 60.0 ohms |
(c) 120 ohms |
(d) 180.0 ohms |
A circular coil of 500 turns of wire has an enclosed area of 
per turn. It is kept perpendicular to a magnetic field of induction 0.2 T and rotated by 180° about a diameter perpendicular to the field in 0.1 sec. How much charge will pass when the coil is connected to a galvanometer with a combined resistance of 50 ohms
|
(a) 0.2 C |
(b) 0.4 C |
(c) 2 C |
(d) 4 C |
Assertion : The cloud in sky generally appear to be whitish.
Reason : Diffraction due to clouds is efficient in equal measure at all wavelengths.
|
(a) If both assertion and reason are true and the reason is the correct explanation of the assertion. |
|
(b) If both assertion and reason are true but reason is not the correct explanation of the assertion. |
|
(c) If assertion is true but reason is false. |
|
(d) If the assertion and reason both are false. |
What causes chromatic aberration?
