Expand this expression (p+q²)²​

 (p + q²)²​ 

We solved this expression by this formula (a + b)² = a² + 2ab + b²

(p + q²)²​ = p² + 2pq² + q4

so this is our required Ans:- p² + 2pq² + q4

Hope you will find this answer helpful..!!

There are how many types of electronics in the world ?

If we talk about electronics in the world, than I think that there is no limitation, because every day there new-new features updates we listening isn't ?.

Actually we can't define the limitations of electronics in the world.

But in current times, the types of electronics is,

1. Digital electronics
2. Analogue electronics
3. Microelectronics
4. Circuit design
5. Integrated circuits
6. Power electronics
7. Optoelectronics
8. Semiconductor devices
9. Embedded systems
10. Audio electronics
11. Telecommunications
12. Nanoelectronics
13. Bioelectronics

How to upgrade window 10 home to window 10 pro for free !

 This is quite easy easy and simple tips to upgrade window 10 home to window 10 pro.

A) So first of all we need to uninstall window 10 home activation from our Pc/ Laptop.

B) Secondly to uninstall window 10 home from our Pc/ Laptop by using CMD.

C) Open CMD as an administrator and type command code.

This command code for uninstall window 10 home:

i] slmgr /upk  press Enter button.

ii] slmgr.vbs /cpky  press Enter button.

iii] slmgr /ckms  press Enter button.

iv] slmgr.vbs /ckms  press Enter button.

After applying this above command, you have to restart your PC/ Laptop. 

And again go in your PC/laptop search box and type CMD and open CMD as an administrator.

By using this command code your PC/ laptop upgrade from window 10 home to window 10 pro.

i] slmgr.vbs /ipk W269N-WFGWX-YVC9B-4J6C9-T83GX  press Enter button.

ii] slmgr.vbs /skms kms.teevee.asia  press Enter button.

iii] slmgr.vbs /ato  press Enter button.

Now your PC/Laptop successfully upgraded to window 10 pro.

Distinguish between ordinary and extra ordinary ray

Ans:

Ordinary rays

1) The ray's which obeys Snell's law and laws of refraction is called ordinary ray.

2) It is denoted by O.

3) It passes undeviated through the crystal.

4) Inside the crystal, speed of O-ray is less than E-ray.

5) The speed is constant in the medium.

6) It gives spherical wavefront.

Extra ordinary ray

1) The ray which does not obey the laws of refraction is called extra ordinary ray.

2) It is denoted by E.

3) It deviates after refraction.

4) Inside the crystal, speed of E-ray is more than O-ray.

5) The speed is not constant in the medium.

6) It gives ellipsoidal wavefront.

What is dichroism ?

 Ans:

1) The property by which some doubly refracting crystals absorb the ordinary rays (O-rays) completely and extraordinary rays whole direction is parallel to the optic axis passing through the crystal, is called dichroism.

2) The crystal possessing dichroism property is called dichroic crystal.

3) Dichroism substance produces linearly polarised light 

4) This property of substance is used to construct a Polaroid.

Example: Tourmaline crystal.

State the main uses of polaroids.

Ans: Uses of Polaroids:

 1) Polaroids are used in motor car head lights to remove head light glare.

2) Used in three dimensional movie cameras.

3) They are used to produce and analyse               polarised light. 

4) They are used as filter in photography. 

5)They are used in window of aeroplanes to control amount of light.

6)  Used in polarising sunglasses (goggles) to protect the eyes from glare of sunlight.

7) They are used to improve colour contrast in old oil paintings.

8) They are used in calculators, watches, monitors of laptops which have LCD screens.

State methods to produce plane polarised light

 Ans: 

a) Reflection 

b) Scattering

c) Refraction 

d) Property of dichroism in calcite or quartz materials.

e) Polaroids

Explain the terms: i) Plane polarised light ii) Plane of vibration iii) plane of polarisation

 Ans:

A) Plane polarised light: The light waves in which vibrations of the electric field vectors are confined only to one plane are called polarised light.

B) Plane of vibration: The plane in which the vibrations of polarised light take place is called as plane of vibration.

C) Plane of polarisation: The plane perpendicular to the plane of vibration in which there are no vibrations of polarised light is called as plane of polarisation.

Why animals are preserved in science laboratory are kept in glass jars not in steel jars?

Because: We can't see, if animals preserved in steel jar. But in case of glass jars we can easily see animals and birds, whatever living things in lab. Those all are kept in glass jars only.

Because of nicely study about particular animals or plant.

And one important thing is that, in wet specimen glass jar, the liquid in which organism are kept is formaldehyde. So formaldehyde is corrosive to carbon steel.

So therefore, steel is not taken in use for preserved organism in jar.