Answer:
Yes it is matter
Explanation:
In physics, usually the word "electricity" isn't really used. "Electric current" is more common, and is defined as the flow of charges, where the charges are held by particles (electrons). Electrons have mass, so they are definitely matter.
Answer: A. silicon and oxygen
Explanation:
The two most abundance elements in earth's crust are silicon and oxygen.
The most abundant element in earth's crust is Oxygen (O) which has a percentage composition of 46.6%. Oxygen is mainly present as silicates, carbonates, sulphates etc.
The second most abundant element in earth's crust is Silicon (Si) which has a percentage composition of 27.7%
. Silicon is present in the form of silicates.
The third most abundant element in earth's crust is aluminium (Al) which has a percentage composition of 8.1 %.
The fourth most abundant element in earth's crust is Iron (Fe) which has a percentage composition of 5.0 %.
Answer:
The magnitude of the magnetic field B is 5.921 T.
Explanation:
Given that,
Length = 4.1 mm



Current 
We need to calculate the magnetic field
Using formula of magnetic field

Put the value into the formula


Hence, The magnitude of the magnetic field B is 5.921 T.
This is because metal is a conductor of electricity while rubber is not (rubber is an insulator). Therefore the metal is more amenable to 'ground' the high charge in the lightning than rubber would. This is also why, when lightning strikes metal, it is safely 'grounded' while if it strikes a non-conductor, most occasionally, it explodes into a fire.
Answer:
r=0.127
Explanation:
When connected in series
Current = I
When connected in parallel
Current = 10 I
We know that equivalent resistance
in parallel R= R₁R₂/(R₂+ R₁)
In series R = R₁+R₂
Given that voltage is constant (Vo)
We also know that relationship between voltage ,current and resistance
V = I R
Vo = I (R₁+R₂) ------------1
Vo = 10 I (R₁R₂/(R₂+ R₁)) -------2
From above equations
10 I (R₁R₂/(R₂+ R₁)) = I (R₁+R₂)
10 R₁R₂ = (R₁+R₂) (R₂+ R₁)
10 R₁R₂ = 2 R₁R₂ + R₁² + R₂²
8 R₁R₂ = R₁² + R₂²
Given that
r = R₁/R₂
Divides by R₂²
8R₁/R₂ = ( R₁/R₂)²+ 1
8 r = r ² + 1
r ² - 8 r+ 1 =0
r= 0.127 and r= 7.87
But given that R₂>R₁ It means that r<1 only.
So the answer is r=0.127