Top answers


Give an example of a negative feedback mechanism in the human body.

When the hypothalamus in the brain detects that the blood is getting too concentrated (not enough water), it stimulates the pituitary gland to release an anti-diuretic hormone (ADH). When it reaches the kidn...
PM
Answered by Paul M. • Biology tutor
7969 Views

How do current and voltage vary in series and parallel circuits, respectively?

In a series circuit, the current is the same throughout; the voltage is split among the components (such as LEDs or resistors) in proportion to the resistance of the components (higher resistance means more ...
PM
Answered by Paul M. • Physics tutor
14984 Views

What is the function of a catalyst in a chemical reaction?

It provides an alternative reaction pathway with a lower activation energy. However, it does not lower the activation energy for the 'normal' reaction without a catalyst.
PM
Answered by Paul M. • Chemistry tutor
19702 Views

Prove that √2 is irrational

Prove by contradiction: Assume negation to be true i.e. √2 is rational Then √2 can be written in the form a/b where a and b are integers with no common factor (the fraction cannot be simplified) => a/b = ...
PM
Answered by Paul M. • Maths tutor
8398 Views

Explain why a transformer is used in electrical power lines.

Power stations use step-down transformers to decrease the voltage of the electrical output. The power lines have a constant resistance (say, R Ohms) which means there is a power loss across the lines given b...
ZM
Answered by Zubair M. • Physics tutor
4026 Views