- ALNICO is an alloy of
ALNICO is a exceptionally hard magnetic material, which is now a days used in making permanent magnets.
- What is the name of the fluorescent material that gives red colour fluorescence?
The magnesium silicate material gives red colour fluorescence. The cerussite (lead carbonate) gives bright green colour fluorescence. The zinc arsenate gives bright colour fluorescence.
- NTPC (National Thermal Power Cooperation) has its only thermal power generating unit in West Bengal at
Farakka super thermal power plant is under the thermal power generating unit of NTPC in West Bengal. The actual place is P.O. Nabarun - 742 236, Dist. Murshidabad, West Bengal.
- Choose the best suitable of Diamagnetic : Paramagnetic::
Except [Water: Air], all the above mentioned magnetic materials are the ferromagnetic type materials. Hence, the example material for diamagnetic is water and the example material for paramagnetic is air.
- Find the odd one out.
Absorptivity, Emissivity and Refractive index the terms which are related with the optical lighting systems. But, the Dielectric strength is related with the capacitor (or) electrostatic field. Hence, the dielectric strength is the odd term of the above things.
- Which of the following is the least desired property in magnetic materials for electrical engineering applications ?
When a magnetic material is subjected to a cycle of magnetization (magnetized first in one direction and later magnetized in opposite direction in a cyclic manner), an energy loss takes place. This energy loss is due to molecular friction in the material. This energy loss is nothing but the hysteresis loss. So, for a large hysteresis material, the point of hysteresis loss (or) magnetic saturation point is high. Hence, the effect of hysteresis loss is less in this case. That is why in the electrical applications, the magnetic material should have larger value of hysteresis loop.
- The number of atoms per unit cell in a B.C.C structure is
We know that the cubic structure has totally 8 corners. Those 8 corners must have 8 atoms in each corner and there is one atom in the center of the cubic structure. The corner atoms are concentrated on the center atom. Hence, the total number of atoms in a BCC structure is 8. So, the number of atoms per unit cell in a BCC structure is [( 1 / 8 ) × 8] + 1 = 2.
- Class B amplifier is biased
Class B Amplifier operation has zero DC bias and hence the transistors are biased at the cut-off. So, each transistor only conducts when the input signal is greater than the base emitter voltage (VBE).
- Cryogenics is a branch of science dealing with which of the following?
Cryogenics is the scientific study of the working of physical things at very low temperatures. Sometimes it approaches with zero degree temperature level and how such temperatures can be achieved and maintained is the main core of cryogenics.