Answer:
Keeping the speed fixed and decreasing the radius by a factor of 4
Explanation:
A ball is whirled on the end of a string in a horizontal circle of radius R at constant speed v. The centripetal acceleration is given by :

We need to find how the "centripetal acceleration of the ball can be increased by a factor of 4"
It can be done by keeping the speed fixed and decreasing the radius by a factor of 4 such that,
R' = R/4
New centripetal acceleration will be,




So, the centripetal acceleration of the ball can be increased by a factor of 4.
Answer:
Electrons and protons are connected with one another in term of charge and size.
Explanation:
- The size of electron and proton is always same in any atom but they possess opposite charge.
- Electron in any atom carries negative charge where as proton carries the positive charge.
- In any neutral atom the charge between electron and proton is balanced along with the size.
- The nucleus of any atom bounds only proton and neutron but the electron is present revolving around the nucleus.
Answer:
The magnetic field along x axis is

The magnetic field along y axis is zero.
The magnetic field along z axis is

Explanation:
Given that,
Length of the current element 
Current in y direction = 5.40 A
Point P located at 
The distance is


We need to calculate the magnetic field
Using Biot-savart law

Put the value into the formula

We need to calculate the value of 



Put the value into the formula of magnetic field


Hence, The magnetic field along x axis is

The magnetic field along y axis is zero.
The magnetic field along z axis is

By giving them an advice and by giving them encouraging and explaining the any theory