In a diffraction pattern by a wire, on increasing diameter of wire, fringe width
|
(a) Decreases |
|
(b) Increases |
|
(c) Remains unchanged |
|
(d) Increasing or decreasing will depend on wavelength |
(a) Decreases
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In a photo cell, the photo-electrons emission takes place
|
(a) After 10–1 sec on incident of light rays |
|
(b) After 10–3 sec on incident of light rays |
|
(c) After 10–6 sec on incident of light rays |
|
(d) After 10–8 sec on incident of light rays |
Two identical point charges are placed at a separation of d. P is a point on the line joining the charges, at a distance x from any one charge. The field at P is E, E is plotted against x for values of x from close to zero to slightly less than d. Which of the following represents the resulting curve
|
(a)
|
(b)
|
(c)
|
(d)
|
A particle A has charge +q and a particle B has charge +4q with each of them having the same mass m. When allowed to fall from rest through the same electric potential difference, the ratio of their speed 
will become
|
(a) 2 : 1 |
(b) 1 : 2 |
(c) 1 : 4 |
(d) 4 : 1 |
If the cathode–anode potential difference in an X-ray tube be 105 V, then the maximum energy of X-ray photon can be
| (a) 105 J | (b) 105 MeV | (c) 10–1 MeV | (d) 105 KeV |
The phenomenon of radioactivity is
|
(a) Exothermic change which increases or decreases with temperature |
|
(b) Increases on applied pressure |
|
(c) Nuclear process does not depend on external factors |
|
(d) None of the above |
64 drops each having the capacity C and potential V are combined to form a big drop. If the charge on the small drop is q, then the charge on the big drop will be
|
(a) 2q |
(b) 4q |
(c) 16q |
(d) 64q |
