Generally, companies conduct three types of written tests:
Aptitude Tests,
Technical Tests
Psychometric tests.
A company can conduct combination of any of these tests.
Aptitude Tests:
Vocabulary and Reading skills, Basic math, analytical, problem-solving skills
Technical Tests;
To test the strength of Basic grounding (engg,mech,civil)technical tests conducted
Psychometric tests:
Just answer these questions honestly ,it is not considered for rejection.