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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The armature of dc motor has 20Ω resistance. It draws current of 1.5 ampere when run by 220 volts dc supply. The value of back e.m.f. induced in it will be
|
(a) 150 V |
(b) 170 V |
(c) 180 V |
(d) 190 V |

The ratio of the intensity at the centre of a bright fringe to the intensity at a point one-quarter of the distance between two fringe from the centre is
|
(a) 2 |
(b) 1/2 |
(c) 4 |
(d) 16 |
A current of two amperes is flowing through a cell of e.m.f. 5 volts and internal resistance 0.5 ohm from negative to positive electrode. If the potential of negative electrode is 10V, the potential of positive electrode will be
|
(a) 5 V |
(b) 14 V |
(c) 15 V |
(d) 16 V |
A current of 1.5 A flows through a copper voltameter. The thickness of copper deposited on the electrode surface of area
in 20 minutes will be (Density of copper = 9000
and E.C.E. of copper = 0.00033 g/C)
|
(a) 2.6 |
(b) 2.6 |
(c) 1.3 |
(d) 1.3 |
The inductance of a coil is 60μH. A current in this coil increases from 1.0 A to 1.5 A in 0.1 second. The magnitude of the induced e.m.f. is
|
(a) 60 |
(b) 300 |
(c) 30 |
(d) 3 |
A curve between magnetic moment and temperature of magnet is
|
(a)
|
(b)
|
(c)
|
(d)
|