P-2 Heredity and Evolution — Science STD 10 — Question

Define the following in terms of gain or loss of hydrogen with one example:

1. Oxidation.
2. Reduction.

What were the limitations of Newlands’ law of octaves?

A concave lens of focal length 15cm forms an image 10cm from the lens. How far is the object placed from the lens? Draw the ray-diagram.

Doctor has prescribed a lens having power +1.5 D for correction of eye defect. What will be the focal length of the lens? What is the type of the lens and what must be the defect of vision?

What do you understand by the term “electromagnetic induction”? Explain with the help of a diagram.

The table given above is based on modern periodic table. write in it the electronic configuration of the first 20 elements below the symbol and write the valency (as shown in a separate box)

Sketch two ways in which solar cells can be connected. Also draw the diagrams to show the arrangement of solar cells to form solar? panel and solar array.
a. Solar cells in series.

Three appliances are connected in parallel to the same source which provides a voltage of 220V. A fuse connected to the source will blow if the current from the source exceeds 10A. If the three appliances are rated at 60W, 500W and 1200W at 220V, will the fuse blow?

Observe the given chart and answer the questions given below.

Element	A	B	C	D
Electronic configuration	2, 1	2, 8	2, 8, 1	2, 8, 8

1. Which elements are in the same row?
2. Which elements have the same column?
3. Which elements are in the 18th column?
4. Which element is more reactive among A and C?
5. Which of the following elements A or B will form compounds?