If threshold wavelength for sodium is 6800Å then the work function will be
|
(a) 1.8 eV |
(b) 2.5 eV |
(c) 2.1 eV |
(d) 1.4 eV |
If threshold wavelength for sodium is 6800Å then the work function will be
|
(a) 1.8 eV |
(b) 2.5 eV |
(c) 2.1 eV |
(d) 1.4 eV |
(a) 1.8 eV
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A beam of electrons is moving with constant velocity in a region having electric and magnetic fields of strength
and 0.5 T at right angles to the direction of motion of the electrons. What is the velocity of the electrons
|
(a) 20 |
(b) 40 |
(c) 8 |
(d) 5.5 |
If identical charges (-q) are placed at each corner of a cube of side b, then electric potential energy of charge (+q) which is placed at centre of the cube will be
|
(a) |
(b) |
(c) |
(d) |
In the circuit shown in figure, each capacitor has a capacity of 3μF. The equivalent capacity between A and B is
|
(a) |
(b) 3 |
(c) 6 |
(d) 5 |
Four charges +Q, -Q, +Q, -Q are placed at the corners of a square taken in order. At the centre of the square
|
(a) E = 0, V = 0 |
(b) E = 0, V ≠ 0 |
(c) E ≠ 0, V = 0 |
(d) E = 0, V ≠ 0 |
Excitation energy of a hydrogen like ion in its first excitation state is 40.8 eV. Energy needed to remove the electron from the ion in ground state is
| (a) 54.4 eV | (b) 13.6 eV | (c) 40.8 eV | (d) 27.2 eV |
A condenser having a capacity of 6mF is charged to 100 V and is then joined to an uncharged condenser of 14 μF and then removed. The ratio of the charges on 6mF and 14mF and the potential of 6mF will be
|
(a) |
(b) |
(c) |
(d) |