Risk of return on investment is higher than other forms of energy generation.
Because the Earth<span> is a sphere, the surface gets much more intense </span>sunlight<span>, hence heat, at </span>the equator<span>than at the poles.</span>
The correct answer of this question is : A) Change alternating current into direct current.
EXPLANATION :
As per the question, we are given vacuum tube. Vacuum tube can be of various types. Normally it contains two electrodes called cathode and anode which are enclosed in an evacuated glass chamber . There are also other types of vacuum tubes which contain extra electrodes like control grid .
The vacuum tube can be used as a rectifier. It means that it can be used as an electronic device which will convert alternating current into direct current. It may be a half wave rectifier or a full wave rectifier. Actually the direct current obtained during the rectification of alternating current is pulsating in nature.
Hence, the correct answer is that a vacuum tube can be used to change alternating current into direct current.
<h2>
The magnitude of the force that acts on a charge of -7.9C at this spot is 2.21 x 10⁶ N.</h2>
Explanation:
Electric field is the ratio of force and charge.
Electric field, E = 280000 N/C
Charge, q = -7.9 C
We have

The magnitude of the force that acts on a charge of -7.9C at this spot is 2.21 x 10⁶ N.
Answer:
Planetary seasons are caused by two factors:
1. axial tilt and
2. variable distance from the sun
Explanation:
Earth's orbit is nearly circular and so has little effect on climate. It's our planet's axial tilt that causes almost all seasonal changes.
You can read further; Planetary seasons