The brilliance of diamond is due to total internal reflection. Diamond has a high refractive index of 2.417 and therefore a small critical angle of 24.5°. Thus, light entering a diamond suffers total internal reflection at nearly all the surfaces.

\(\\ \mu =\cfrac { c }{ v } =\cfrac { sini }{ sinr } \) 
It follows that: v of sin r Since r is minimum in medium R, therefore, sin r and hence the velocity of light is minimum in medium R.

Yes, since magnification depends upon the focal length and focal length depends on the color and different colours have different wavelengths (i.e., different refractive indices.)
\(\cfrac { 1 }{ f } =\left( \mu -1 \right) \left( \cfrac { 1 }{ { R }_{ 1 } } -\cfrac { 1 }{ { R }_{ 2 } } \right) \) 
(By Lens Makers Formula) Also, magnification of the compound microscope
\(M=\cfrac { -L }{ { f }_{ o } } \left( 1+\cfrac { D }{ { f }_{ e } } \right) \)

Optical fibres consists of inner part called core and outer part called cladding(or) sleeving.

The radius of the sphere of which the spherical mirror is a part is called the radius of curvature (R) of the mirror.

"Photoelectric effect" shows the quantum nature of electromagnetic radiation.

Industrial robots are used for welding, cutting, robotic water jet cutting, robotic laser cutting, lifting, sorting, bending, manufacturing, assembling, packing, transport, handling hazardous materials like nuclear waste, weaponry, laboratory research, mass production of consumer and industrial goods.

The natural structure provides a blueprint for creating ultra-durable synthetic materials that could be useful for mechanical components in electronics, and in other devices that undergo repetitive movement, abrasion and contact stress.

The signal wave that results on superimposing the modulating wave on the carrier wave is called modulated wave.

(i) Fiber optic cables are more fragile when compared to copper wires.
(ii) It is an expensive technology.

Digital electronics deals with logical operations. The variables are called logical variables

The process in which alternating voltage or alternating current is converted direct voltage or direct current is called rectification.

K.E of the electron = 13.6 eV
P.E is equal to twice its K.E
P.E of the electron = -13.6 x 2 = -27.2 eV 

(i) Alpha ray has high ionizing power.
(ii) α - particle has a large mass and large nuclear cross-section. So it has high ionizing power.

(i) Speed of Electromagnetic wave \(=\frac{Peak\ value\ of\ Electric\ field}{Peak\ value\ of\ magnetic\ field}\)
\(c=\frac { { E }_{ 0 } }{ { B }_{ 0 } } \)
(ii) Yes, As Electromagnetic waves contain both electric and magnetic fields, there is a non-zero energy density associated with it.
\(E=\frac { hc }{ \lambda } \)
Momentum p \(=\frac{Total\ energy\ transferred\ to\ the\ surface}{Velocity\ of\ light\ in\ vacuum}\)
i.e.p = \(\frac{U}{c}=mc\)
U - total energy transferred to the surface.
EM waves carry not only energy and momentum but also angular momentum.

(i) After disconnecting the battery, the charge on capacitor remains constant.
∴ energy stored capacitor \(\left( U=\frac { { q }^{ 2 } }{ 2C } \right) \)
(ii) As the battery remains connected, the potential difference remains constant.
Hence energy stored U = \(\frac{1}{2}\) CV² decreases.

The galvanometer is said to be sensitive if it shows large scale deflection even though a small current is passed through it or a small voltage is applied across it.

Magnetic field is the region or space around every magnet within which its influence will be felt by keeping another magnet in that region.
\(\vec { B } =\frac{1}{q_m}\vec{E}\)
Its unit is N A^-1m^-1

(i) As the plate oscillate, the changing magnetic flux through the plate produces a strong eddy current in the direction, which opposes the cause.
(ii) Also copper being diamagnetic substance, it gets magnetised in the opposite direction, so the motion of copper plate is stopped.

\(I=\cfrac { E }{ R+r } \)

An alternating voltage is the voltage which changes polarity at regular intervals of time and the direction of the resulting alternating current also changes accordingly.

The resistors value of carbon resistors changes considerably during storage and use.

Seebeck discovered that in a closed circuit consisting of two dissimilar metals, when the junctions are maintained at different temperatures an emf (potentiaal difference) is developed.

The resistivity of materials is
(i) inversely proportional to the number density (n) of the electrons
(ii) inversely proportional to the average time between the collisions \(\left( \tau \right) \)

The instantaneous current I is defined as the limit of the average current \(\Delta t\rightarrow 0\) 
\(I=\underset { \Delta t-0 }{ lim } \cfrac { \Delta Q }{ \Delta t } =\cfrac { dQ }{ dt } \)

Capacitor is a device used to store electric charge and electrical energy.