Answer:
Number of turns in secondary will be 7
Explanation:
We have given primary voltage 
Number of turns in the primary is 
Secondary voltage is given 
We have to find the number of turns in secondary
We know that 
So 

As the number of turns can not be in decimal so number of turns will be 7
Answer:
B Eight light-minutes
Explanation:
In the case when the distance separated earth and the sun so here we orbit the sun for a 150 million km distance and the light moves would be 300,000 kilometers per second
Now divide this
= 150 million ÷ 300,000 kilometers per second
= 500 seconds
This 500 seconds represent 8 minutes and 20 seconds
Hence, option B is correct
Answer:
The answer is below
Explanation:
The speed of the boat in still water is perpendicular to the speed of the water flow. Therefore the speed relative to the ground (V), the speed of flow and the speed of the boat in still water form a right angled triangle. Hence the speed relative to the ground is given as:
V² = 56² + 126²
V² = 19012
V = 137.9 m/s
The teeth and threads creates roughness that increases the friction between the tire and the road.