Choose the correct alternative (a), (b), (c) or (d) for the question given below:
In the figure, a charge Q is fixed. another charge q s moved along a circular arc MN of radius r around it, from the point M to the point N such that the length of the arc MN = l. The work done in this process is:
zero
A carbon resistor has coloured bands as shown in fig. 2 below. The resistance of the resistor is:
26 10%
26 5%
260 5%
260 10%
A solenoid L and a resistor R are connected in series to a battery, through a switch. When the switch is put on, current I flowing through it varies with time t as shown in which of the graphs given below:
Two thin lenses having optical powers of -10 D and +6 D are placed in contact with each other. The focal length of the combination is:
+0.25 cm
-0.25 cm
+0.25 cm
-0.25 m
Total energy of an electron in the ground state of hydrogen atom is -13.6 eV. Its total energy, when hydrogen atom is in the first excited state, is:
+13.6 eV
+3.4 eV
-3.4 eV
-54.4 eV
A charged oil drop weighing 1.6 x 10^{-15} N is found to remain suspended in a uniform electric field intensity 2 x 10^{3} NC^{-1}.^{ }Find the charge on the drop?
For a metallic conductor, what is the relation between current density (J), conductivity () and electric field Intensity (E)?
In the figure given below, find the value of resistance X for which points A and B are at the same potential:
A coil has self-inductance of 0.05 Henry. Find the magnitude of the emf induced in it when the current flowing through it is changing at the rate of 100 A s^{-1}.