Both, chemical change and physical change.

As the wire is bent in the form of a closed circle, it will be have like two resistors of 5\(\Omega \) each, connected in parallel. Therefore, the equivalent resistance can be calculated as:
\(\frac { 1 }{ R_{ eq } } =\frac { 1 }{ { R }_{ 1 } } +\frac { 1 }{ { R }_{ 2 } } \)
\(\frac { 1 }{ R_{ eq } } =\frac { 1 }{ 5 } +\frac { 1 }{ 5 } \)=\(\frac { 1 }{ R_{ eq } } =\frac { 2 }{ 5 } \)
\(\frac { 1 }{ R_{ eq } } =\frac { 5 }{ 2 } =2.5\Omega \)
The effective resistance between the two points at the ends of an diameter of the circle is 2.5 \(\Omega \).

\(Refractive\quad index\quad of\quad glass=\frac { Speed\quad of\quad light\quad in\quad vaccum }{ Speed\quad of\quad light\quad in\quad glass } \\ 1.65=\frac { { 3\times 10 }^{ 8 } }{ { v }_{ g } } \\ { v }_{ g }=\frac { { 3\times 10 }^{ 8 } }{ { v }_{ g } } =1.8\times { 10 }^{ 8 }m/s\)

(a) Reflection of light
(b) Refraction of light.

(a) Image is virtual and erect.
(b) Image is diminished.

It is the power of a lens of focal length one metre.

Image is real

Between pole and principal focus

50%

Urey and Miller.

It is believed that features in dinosaurs might have provided insulation in cold weather but later on became useful for flights in birds.

Male - I^A I^B Female - I^O I^A Blood groups will be :
(i) A (ii) A (iii) B (iv) AB

Gallium and caesium

Carbon and highly reactive metals such as sodium, calcium, aluminium are used as reducing agents to reduce metal into metal.

Gold and silver.