You are correct that it requires (String,String) the one that you have provided, / is considered as escape character. When you provide the path it contains / but in order for program to understand you must use //.
Hence, instead of writing
System.setProperty("webdriver.chrome.driver","C:\Users\Sradha\Downloads\chromedriver.exe");
if you use
System.setProperty("webdriver.chrome.driver","C:\\Users\\Sradha\\Downloads\\chromedriver.exe");
This will work fine.