Stars are located at a distance which are measured in terms of light years. Light year is an Astronomical unit used to measure distance between distant Celestial bodies.
1 light year = 9460730472580<span>800 metres
But no star is located at a distance of 1 light year. Some stars are located at millions of light years and light travels ~ 3 x 10</span>⁸ m/s. Thus light takes time to reach our atmosphere.
The answer is to u question is: C
Remark
All the statements are correct except for B
B is wrong because the Force is inversely proportional to the square of the distance.
D is correct. That's what Newton saw when he watched the apple fall. The apple did all the moving.
A is correct. The formula is
F = G*m1*m2/r^2
If r is held constant the formula becomes
F = k * m1 * m2 where k = G/r^2
C is true as well, but it sure decreases in strength because of the distance and the smallness of G.
Answer:
Turns of the primary coil: 500
Current in the primary coil: Ip= 0.01168A
Explanation:
Considering an ideal transformer I can propose the following equations:
Vp×Ip=Vs×Is
Vp= primary voltaje
Ip= primary current
Vs= secondary voltaje
Is= secondary current
Np×Vs=Ns×Vp
Np= turns of primary coil
Ns= turns of secondary coil
From these equations I can clear the number of turns of the primary coil:
Np= (Ns×Vp)/Vp = (20×120V)/4.8V = 500 turns
To determine the current in the secondary coil I use the following equation:
Is= (1.4W)/4.8V = 0.292A
Therefore I can determine the current in the primary coil with the following equation:
Ip= (Vs×Is)/Vp = (4.8V×0.292A)/120V = 0.01168A
