Dell Original 65W 7.4mm Pin Adapter for Inspiron 15 3542
New Dell AC Adapter Charger Inspiron 15, 15-3542,15-3537 Power Adapter 19.5V 3.34A 65W with Pin Size 4.5MM x 3.0MM, please note that Older Version for these models takes the bigger pin size:
Dell Inspiron 15 3542 65W Laptop Charger Power Adapter