PART - 2 CH - 8 Heredity — Science STD 10 — Question

Identify the device used as a spherical mirror or lens in the following cases, when the image formed is virtual and erect in each case.
(1) An object is placed between the device and its principal focus. The image formed is enlarged and behind the device.
(2) The object is placed between the principal focus and device. The image formed is enlarged and on the same side as that of the object.
(3) The object is placed at finite distance from the device (i.e., between infinity and device). The image formed is diminished and lies between the principal focus and optical centre and on the same side as that of the object.
(4) The object is placed at finite distance from the device (i.e., between infinity and device). The image formed is diminished and lies between the pole and principal focus as well as behind it.

Draw a ray diagram showing the path of a ray of light when it enters at oblique incidence from water into air.

What is the function of blood capillaries?

What processes would you consider essential for maintaining life?

State the function of the iris.

Advanced agricultural practice leads to excessive use of fertilisers, pesticides and irrigation. Use of such agricultural products can cause some health issues in human beings. Uncontroled use of chemicals can also cause adverse effect on our environment.
Questions :
(1) Name the ecological process involved in the above case.
(2) How is soil affected by this phenomena ?
(3) Why is pesticide persist for long time in an environment?

State two serious hazards of electricity.

Which metal does not release hydrogen gas with nitric acid? Why?

What is a lens? OR Define a lens.