Short Answer TypeVoltage applied between cathode and anode of an X-ray tube is 18 kV. Calculate the minimum wavelength of the X-rays produced.
In a nuclear reactor, what is the function of:
i) The moderator
ii) The control rods
iii) The coolant
The atomic mass of Uranium 
is 238.0508 u, while that of thorium 
is 234.0436 u, and that of Helium 
is 4.0026 u. Alpha decay converts 
and 
as shown below.
Determine the energy released in this reaction.
ii) What is a neutrino?
In semiconductor physics, what is meant by:
i) a rectifier
ii) an amplifier
iii) an oscillator
Long Answer TypeAn alternating emf of 110 V is applied to a circuit containing a resistance R of 80 ohm and inductor L in series. The current is found to lag behind the supply voltage by an angle 
. Find the:
i) Inductive Reactance
ii) Impedence of the circuit
iii) Current flowing in the circuit
iv) If the inductor has a coefficient of self inductance of 0.1 H, what is the frequency of the applied emf
i) What is meant by the dispersive power of a transparent material?
ii) Show that, two thin lenses kept in contact, form an achromatic doublet if they satisfy the condition:
where the terms have their usual meanings.
With the help of a diagram, show how you can use several NAND gates to obtain an OR gate.
Construction of OR gate using NAND gates:
i) If the two inputs of a NAND gate are joined together, it works as a NOT gate.
ii) Now, on inverting the inputs A and B using two NOT gates (obtained from two NAND gates) and the resulting outputs 
is fed to a third NAND gate, then the final output Y is same as an OR gate.
Tha arrangement of gates is as shown below:
The truth table for the OR gate using NAND gate is given as:
| A | B |  |
 |
Y |
| 0 | 0 | 1 | 1 | 0 |
| 0 | 1 | 1 | 0 | 1 |
| 1 | 0 | 0 | 1 | 1 |
| 1 | 1 | 0 | 0 | 1 |
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