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 metal rod of length 2 m is rotating with an angular velocity of 100 rad/sec in a plane perpendicular to a uniform magnetic field of 0.3 T. The potential difference between the ends of the rod is
|
(a) 30 V |
(b) 40 V |
(c) 60 V |
(d) 600 V |
If two lenses of +5 diopters are mounted at some distance apart, the equivalent power will always be negative if the distance is
|
(a) Greater than 40 cm |
(b) Equal to 40 cm |
|
(c) Equal to 10 cm |
(d) Less than 10 cm |
The radius of curvature of convex surface of a thin plano-convex lens is 15 cm and refractive index of its material is 1.6. The power of the lens will be
|
(a) + 1D |
(b) -2D |
(c) +3D |
(d) +4D |
If in the circuit shown below, the internal resistance of the battery is 1.5 W and VP and VQ are the potentials at P and Q respectively, what is the potential difference between the points P and Q

|
(a) Zero |
(b) 4 volts (VP > VQ) |
(c) 4 volts (VQ > VP) |
(d) 2.5 volts (VQ > VP) |
This symbol represents

|
(a) NOT gate |
(b) OR gate |
(c) AND gate |
(d) NOR gate |
An electron moving with a speed u along the positive x-axis at y = 0 enters a region of uniform magnetic field which exists to the right of y-axis. The electron exits from the region after some time with the speed v at co-ordinate y, then
|
(a) v > u, y < 0 |
(b) v = u, y > 0 |
(c) v > u, y > 0 |
(d) v = u, y < 0 |