If an electric train is travelling south, then which way is the smoke going?

The more of this there is, the less you see. What is it?

Can anyone tell me a word in the English dictionary which has a silent 'z'?

In the image below, can you find the value of an angle(y)

Which English verb becomes past tense just by rearranging the letters?

Can you find out the remainder when 3^300 is divided by 5?

Spot the cat in the picture below

Dwayne Johnson was running away with the loot from a heist in his car along with Vin Diesel. One tire was punctured and he dropped down to replace it. While changing the wheel, he dropped the four nuts that were holding the wheel and they fell into a drain. Vin Diesel gave him an idea using which they were able to drive till the rendezvous point.

What was the idea ?

You can see it everyday, But cannot touch it at will. What is it?

One is to three as three is to five and five is to four and four is the magic number.
What is the pattern?