C. because you need voltage in a circuit to cause current.
<span>The point in a planet's orbit where it is farthest from the Sun is called the Aphelion. On the other hand, if this planet is Earth, </span>Earth is closest to the sun in about 2 weeks after the solstice of December. This point is called the Perihelion contrary to Aphelion. The planet will be called the apogee or perigee depending on which point it is in.
Answer:
Squamous epithelium has cells that are wider than their height (flat and scale-like). ... Cuboidal epithelium has cells whose height and width are approximately the same (cube shaped). Columnar epithelium has cells taller than they are wide (column-shaped).
Answer : The half-life of this substance will be, 45 minutes.
Explanation :
First we have to calculate the value of rate constant.
Expression for rate law for first order kinetics is given by:

where,
k = rate constant = ?
t = time passed by the sample = 90.3 min
a = initial amount of the reactant = 400
a - x = amount left after decay process = 100
Now put all the given values in above equation, we get


Now we have to calculate the half-life of substance, we use the formula :



Therefore, the half-life of this substance will be, 45 minutes.