Answer:
Option (A) and (F)
Explanation:
As the liquid cools down, it means the temperature decreases the density of the liquid increases in most o the cases.
Now the volume is inversely proportional to the density of substance so density increases.
Answer:
55.8 m/s
Explanation:
= Actual frequency of sound emitted by car
= frequency observed when the car moves = 
= Speed of sound = 343 m/s
= Speed of car
Frequency observed is given as


A transformer is used to increase or decrease a voltage. BUT ... it has to be an AC voltage, or the transformer doesn't work.
The most crucial information would be its atomic number.