Assertion: The size and shape of the rigid body remains unaffected under the effect of external forces.
Reason: The distance between two particles remains constant in a rigid body.
If both assertion and reason are true and reason is the correct explanation of assertion
If both assertion and reason are true but reason is not the correct explanation of assertion
If assertion is true but reason is false
If both assertion and reason are false
The dimensions of specific resistance are
[ M L2 T-2 A-1 ]
[ M L3 T-3 A-2 ]
[ M L3 T-2 A-1 ]
[ M L2 T-2 A-2 ]
Four charges arc arranged at the corners of a square as shown in the figure. The direction of electric field at the centre of the square is along
DC
BC
AB
AD
A conducting sphere of radius R carrying charge Q lies inside an uncharged conducting shell of raius 2R. If they are joined by a metal wire, the amount of heat that will be produced is
Black holes in orbit around a normal star are detected from earth due to the frictional heating of infalling gas into the black hole, which can reach temperatures greater than 106 K. Assuming that the infalling gas can be modelled as a blackbody radiator, then the wavelength of maximum power lies
in the visible region
in the X-ray region
in the microwave region
in the gamma-ray region of electromagnetic spectrum
What is the energy stored in the capacitor between terminals a and b of the network shown in the figure? ( capacitance of each capacitor C = 1 μF)
12.5 μJ
Zero
25 μJ
50 μJ
A moving coil galvanometer has a resistance of 900 Ω. In order to send only 10 % of the main current through this galvanometer, the resistance of the required shunt is
0.9 Ω
100 Ω
405 Ω
90 Ω
A current I1 carrying wire AB is placed near another long wire CD carrying current I2. If wire AB is free to move, it will have
rotational motion only
translational motion only
rotational as well as translational motion
neither rotational nor translational motion
C.
rotational as well as translational motion
Since the magnetic field due to the current through wire CD at a various locations on wire AB is not uniform, therefore the wire AB, carrying current I1 is subjected to variable magnetic field due to which, neither the force nor the torque on the wire AB will be zero. As a result of which the wire AB will have both translational and rotational motions.
A coil of wire of a certain radius has 100 turns and self inductance of 15 mH. The self inductance of a second of a second similar coil of 500 turns will be
75 mH
375 mH
15 mH
none of these