few question related to nodejs memory useage and garbage collection

Question

I have few questions related to memory usage in nodejs

1. In the MVC project structure, can require file increase memory uses over time? eg :

   In server.js (main file i.e entry point of server)

   let user = require("./routes/user-r.js") //1kb during initial run,will it increase in size as number of hit increase?
   app.use("/",user);
   

   In routes/user-r.js

   let user_c = new (require("../controller/user-c.js")) //1kb during initial run,will it increase in size as a number of hit increase?
   module.export = (app) =>{
   
    // require above or inside below code does it make any difference in memory usage perspective?
    //  let user_c = new (require("../controller/user-c.js")) 
   
      route.get("/", user_c.Test())
   }
   

2. In controller creating variable clear automatically after it returns response? eg:

   In controller/user-c.js

   let path = require("path") // will this increase memory size, every time when this controller call from routes
   class User {
      constructor(){
         this.user_m = new (require("./user-m.js") // is constructor remove this file from memory when not in use? i.e garbage collection remove this variable from memory
      }
      Test(){
          let x = "this is testing for memory" // is this variable clear from memeory every time?
      }
   

   }

3. when garbage collection runs automatically? i.e after a certain default memory limit or after a response return by the controller

4. what happens if the server has continuously hit in the 10-sec interval will garbage collection runs automatically?

5. requiring the same file in a different variable can use twice memory size or same eg :

   let t = require("path"); let c = require("path"); is both variable consume memory ?

6. suppose 3 controller files, consider as user-c, management-c , test-c. all these file requiring path ( require("path")) and storing it into 3 different variable. will it increase memory uses 3 times?

7. is it possible to make a test file that can check for memory leakage?

8. is there any npm packages that can check for memory usage?