Answer : Yes, distance measurements based on the speed of light used for objects in space.
Explanation : A light year is measurement of distance that light travel in a one year.
In a one year light travels 9460000000000 kilometer.
We know that, speed of light is
and time is 31536000 seconds in 1 year
so, distance = speed of light X time
Now, the light year is
Example : The nearest star to earth is about 4.3 light year away.
Answer:
1. a
2. b
3. b
Explanation:
1.
Resistance is the property of a conductor to offer resistance to the flow of current. The lower the resistance better is the conductivity of wire.
We know that the resistance of a wire depends on several factor which are inter-connected by an equation as:
where:
R = resistance of the wire
length of the wire
cross sectional area of the wire
from the above relation we observe that
2.
As the collision between the electrons and protons increases the speed of the flow of charges will decrease because the opposite charges attract each other and as we know that electrical current is the rate of flow of charge.
3.
Heating up of wire due to sunlight will cause lattice vibration in the conductor and will obstruct the movement of the charges which build up electric current, hence increasing the resistance of conductivity.