image distance,di=10 cm
object distance,do=20cm
magnification, m=di/do
=10/20
=0.5
since the image is virtual, magnification is negative.
therefore m=-0.5
It's called texture, meaning how something feels.
I believe the answer is C. protoplanetary disc. Let me know if this helps
Answer : The time required is, 16.1 minutes.
Explanation :
First we have to calculate the amount of heat required to increase the temperature is:


where,
Q = amount of heat required = ?
m = mass
= density of air = 
V = volume of air
C = specific heat of air = 
= change in temperature = 
Now put all the given values in above formula, we get:



Now we have to calculate the time required.
Formula used :

where,
t = time required = ?
Q = amount of heat required = 
P = power = 1500 W
Now put all the given values in above formula, we get:


Thus, the time required is, 16.1 minutes.
Answer:
The value is 
Explanation:
From the question we are told that
The length of the wire is 
The current density is 
The conductivity is
Generally conductivity is mathematically represented as

Here R is the resistance which is mathematically represented as

Here I is the current which is mathematically represented as

So

And

=> 
=> 
=> 
=> 