X-rays are in nature similar to
| (a) Beta rays | (b) Gamma rays | (c) de-Broglie waves | (d) Cathode rays |
X-rays are in nature similar to
| (a) Beta rays | (b) Gamma rays | (c) de-Broglie waves | (d) Cathode rays |
(b) Gamma rays
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The current in a triode at anode potential 100 V and grid potential – 1.2 V is 7.5 mA. If grid potential is changed to – 2.2 V, the current becomes 5.5 mA. the value of trans conductance (gm) will be
|
(a) 2 mili mho |
(b) 3 mili mho |
(c) 4 mili mho |
(d) 0.2 mili mho |
A hole in a P-type semiconductor is
| (a) An excess electron | (b) A missing electron |
|
(c) A missing atom |
(d) A donor level |
A concave lens and a convex lens have same focal length of 20 cm and both put in contact this combination is used to view an object 5 cm long kept at 20 cm from the lens combination. As compared to object the image will be
|
(a) Magnified and inverted |
(b) Reduced and erect |
|
(c) Of the same size and erect |
(d) Of the same size and inverted |
The mass defect for the nucleus of helium is 0.0303 a.m.u. What is the binding energy per nucleon for helium in MeV
|
(a) 28 |
(b) 7 |
(c) 4 |
(d) 1 |
The threshold wavelength for photoelectric emission from a material is 5200 Å. Photo-electrons will be emitted when this material is illuminated with monochromatic radiation from a
|
(a) 50 watt infrared lamp |
(b) 1 watt infrared lamp |
|
(c) 50 watt ultraviolet lamp |
(d) Both (c) and (d) |
Tangent galvanometer is used to measure
| (a) Steady currents | (b) Current impulses |
| (c) Magnetic moments of bar magnets | (d) Earth's magnetic field |
A tall man of height 6 feet, want to see his full image. Then required minimum length of the mirror will be-
The work function of a photoelectric material is 3.3 eV. The threshold frequency will be equal to
|
(a) 8 |
(b) 8 |
(c) 8 |
(d) 8 |