Answer:
Astronomer
Explanation:
A scientist who studies the objects in the sky, including planets, galaxies, black holes, and stars, is called an astronomer. These days, the terms astronomer and astrophysicist are used interchangeably, to talk about any physicist who specializes in celestial bodies and the forces that affect them.
Answer:
I think it's 3
Explanation:
Can I have brainliest? It would help me out, if not thanks anyways! Hope this helped and have a nice day!
Explanation:
We have,
Surface area, 
The current varies wrt time t as :

(a) At t = 2 seconds, electrical charge is given by :

(b) Current is given by :

Instantaneous current at t = 1 s is,

(c) Current is, 
Current density is given by electric current per unit area.

Therefore, it is the required explanation.