A longitudinal wave is represented by . The maximum particle velocity will be four times the wave velocity if
A block of ice at temperature -20°C is slowly heated and converted to steam at 100°C. Which of the following diagram is most appropriate ?
Two black bodies at temperatures 327°C and 427°C are kept in an evacuated chamber at 27°C. The ratio of their rates of loss of heat are
A point charge +q is placed at the centre of a cube of side L. The electric flux emerging from the cube is
zero
In the figure below, the capacitance of each capacitor is 3 µF. The effective capacitance between A and B is
3 µF
6 µF
5 µF
A wire of resistance R is elongated n-fold to make a new uniform wire. The resistance of new wire
nR
n2R
2nR
2n2R
The ratio of magnetic field and magnetic moment at the centre of a current carrying circular loop is x. When both the current and radius is doubled the ratio will be
x/8
x/4
x/2
2x
A.
x/8
The magnetic field at the centre of a current carrying loop is given by
The magnetic moment at the centre of current carrying loop is given by
When both the current and the radius are doubled, the ratio becomes
The current through a coil of self-inductance L = 2mH is given by i = t2e-t at time t. How long it will take to make the emf zero ?
1 s
2 s
3 s
4 s
The magnetic flux through a loop of resistance 10 Ω is given by (=5t2 − 4t+ 1 Wb). How much current is induced in the loop after 0.2 s ?
0.4 A
0.2 A
0.04 A
0.02 A