Answer:

Explanation:
Velocity of wave in stretched string is given by the formula

here we know that
T = 4 N
also we know that linear mass density is given as

so we have

now the tension in the string is double
so the velocity is given as


What's your question? is it seprete questions
Answer: I do
Explanation:
Resistance opposes current thereby reducing the amount of current that flows through a circuit. In other words, it leads to a loss of electrical energy.
Ideally speaking, a good circuit should have no internal resistance as this would lead to more energy having to be supplied to overcome that resistance. External resistance however, is not a bad thing. For instance, oxygen being removed from lightbulbs.
Answer:
So percentage error will be 2 %
Explanation:
We have given initial value of acceleration due to gravity 
And final value of acceleration due to gravity 
We have to find the percentage error
We know that percentage error is given by 
So
%