First you will need to add cordova splash screen plugin.
Open terminal and type command

$ cordova plugin add cordova-plugin-splashscreen
now open config.xml file and add the following entries in this file
<preference name = "SplashScreen" value = "screen" />
// how long splash screen will be displayed
<preference name = "SplashScreenDelay" value = "3000" />
//If SplashMaintainAspectRatio value is false image will get  stretched
<preference name = "SplashMaintainAspectRatio" value = "true" />

Build your app and emulate.