Answer :

Golden Rules of Journal

Personal account rule

Debit- The receiver.  

Credit- The giver.  

Real account rule

Debit- What comes in.  

Credit- What goes out.  

Nominal account rule

Debit- All expenses and losses.  

Credit- All incomes and gains.  

Now

The journal; entry will be

Computers A/C      DR

          To Bank A/C      

(Being Purchased computer against cheque from Computer Mart, Noida.)

Short explanation

Payment has been made by cheque therefore, no creditors will be created in the name of Computer Mart and instead bank account will be credited and Computer will debited.