Wings of a morpho butterfly, peacock feathers, lotus leaf surface and sources of parrot fish's bite are some of the natural nano particles.

A = 1, B = 0, C = 1
y = A + B, y = (A + B).C
y = (1 + 0).1 ⇒ y = 1

d' = 2d, β' = β, D' = ?
W.K.T, Fringe width
\(\beta = \frac{D\lambda}{d} \Rightarrow D' = \frac{Dd'}{d}\)
\(D' = \frac{D2d}{d}=2D\)

\(tan \ I=\frac{B_V}{B_H}=1\)
∴ I = 45^o

Magnetic moment,
p'_m = ml
From figure, \(l=\frac{\pi r}{3}\)
\(\therefore r=\frac{3l}{\pi}\)
∴ New magnetic moment,
p'_m = m x r
\(=m\times \frac{3l}{\pi}=\frac{3}{\pi}ml\)
∴ p'_m = \(\frac{3}{\pi}p_m\)

Output at 1 = AB
Output at 2 = \(\overline{A+B}\)
Output at y  = AB +  \(\overline{A+B}\)

A	B	A.B	A + B	\(\overline{A+B}\)	AB + \(\overline{A+B}\)
0	0	0	0	1	1
0	1	0	1	0	0
1	0	0	1	0	0
1	1	1	1	0	1

NAND and NOR gates are known as universal gates because any other logic gate can be made from NAND or NOR gates.

(i) IR radiation:
(i) It is used to produce dehydrated fruits, in green houses to keep the plants warm, heat therapy for muscular pain or sprain, TV remote as a signal carrier, to look through haze fog or mist.
(ii) It is used in night vision or infrared photography.
(ii) Microwaves:
It is used in radar systems for aircraft navigation, speed of the vehicle microwave oven for cooking and very long distance wireless communication through satellites.
(iii) UV radiation:
It is used to destroy bacteria in sterilizing the surgical instruments, burglar alarms, to detect the invisible writing, finger prints and also in the study of atomic structure.

\(\frac{\mathrm{I}_{\max }}{\mathrm{I}_{\min }}=\frac{36}{1}\)
If a₁ and a₂ are their amplitudes,
\(\frac{\mathrm{I}_{\max }}{\mathrm{I}_{\min }}=\frac{\left(\mathrm{a}_{1}+\mathrm{a}_{2}\right)^{2}}{\left(\mathrm{a}_{1}-\mathrm{a}_{2}\right)^{2}}=\frac{36}{1}\)  (or) \(\frac{a_{1}+a_{2}}{a_{1}-a_{2}}=\frac{6}{1}\) 
6a₁ - 6a₂  = a₁ + a₂ 
5a₁ - 7a₂ = 5a₁ = 7a₂  
\(\frac{a_{1}}{a_{2}}=\frac{7}{5}\) 
a₁ : a₂ = 7 : 5 

(i) Stretch out forefinger, the middle finger and the thumb of the left hand such that they are in three mutually perpendicular directions.
(ii) If the forefinger points in the direction of magnetic field, the middle finger in the direction of the electric current, then thumb will point in the direction of the force experienced by the conductor.

Advantages of Robotics:
(i) Robots are more precise and error free in performing the task.
(ii) Robots never get tired like humans. It can work for 24 x 7. Hence absenteeism in work place can be reduced.
Disadvantages of Robotics:
(i) Unemployment problem will increase.
(ii) Robots can perform defined tasks and cannot handle unexpected situations.

(i) De Morgan's First theorem states that the complement of the sum of two inputs is equal to the product of its complements.
\(\overline{\mathrm{A}+\mathrm{B}}=\overline{\mathrm{A}} \cdot \overline{\mathrm{B}}\)
(ii) The second theorem states that the complement of the product of two inputs is equal to the sum of its complements.
\(\overline{\mathrm{A} \cdot \mathrm{B}}=\overline{\mathrm{A}}+\overline{\mathrm{B}}\)

S.No	Fresnel diffraction	Fraunhofer diffraction
(i)	Spherical or cylindrical wave front undergoes diffraction.	Plane wavefront undergoes diffraction.
(ii)	Light wave is from a source at finite distance.	Light wave is from a source at infinity.
(iii)	For laboratory conditions, convex lenses need not be used.	In laboratory conditions, convex lenses are to be used.
(iv)	Difficult to observe and analyse.	Easy to observe and analyse.
(v)

sno	Dia magnetic materials	Para magnetic materials	Ferromagnetic materials
(i)	In diamagnetic materials each electron orbit has finite orbital magnetic dipole moment.	In paramagnetic materials each atom (or) molecule has net magnetic dipole moment.	The ferromagnetic materials have net dipole moment as in a paramagnetic material.
(ii)	Since the orbital planes are oriented in random manner, the vector sum of magnetic moments  is zero.	Due to the random orientation of these magnetic moments, the net magnetic moment of the material is zero.	Within each domain, the magnetic moments are spontaneously aligned in a direction.
(iii)	The resultant magnetic moment for each atom is zero.	There is net magnetic dipole moment induced in the direction of the applied field.	Since the direction of magnetisation varies from domain to domain, net magnetisation of the specimen is zero.

When the spectrum obtained from the Sun is examined, it consists of large number of dark lines (line absorption spectrum). These dark lines in the solar spectrum are known as Fraunhofer lines.