(i) Purchases of Rs 10,000 from Mohan recorded as Rs 1,000.
(ii) Payment to Varun recorded as payment to Tarun and do not effect trial balance.

(i) Errors of Commission: When any transaction is incorrectly recorded either wholly or partly, error of commission arises. It may consist of incorrect posting, calculation and balancing. Such error is committed when an item is posted to the credit instead of to the debit of an account or vice-versa. For example: A credit purchase of Rs 675 is entered in the Purchases Book as Rs 576 or posting of Rs 2,000 to the credit of Ranu instead of the credit of Manish.
(ii) Errors of Principle: Error of principle is committed when a transaction is recorded in a fundamentally incorrect manner. Such error involves an incorrect allocation of expenditure or receipt between capital and revenue. For example: freight paid for bringing new machinery is posted to freight account or asset purchased is recorded in the purchases book.

Errors of commission is committed in such a way that the double entry is not completed, or a wrong entry is made in the books. For example: if a posting is made to a wrong account or to a wrong side in the same account or in a different account or totals are wrong. Such an error affects agreement of Trial Balance. Errors of principle, on the other hand, violates the rule of accountancy. This involves wrong distinction between expenses and assets and between incomes and liabilities i.e., between revenue and capital items. This does not affect the agreement of Trial Balance.

Yes, a trial balance is merely a proof of arithmetical accuracy as there are various errors which are not disclosed by a trial balance as follows:
(i) Errors of Principle: In the absence of full knowledge of double entry system errors made are not reflected in trial balance. Like capital expenditure treated as revenue expenditure.
(ii) Errors of Omission: If any entry has been forgotten to be recorded in the books of original entry or ledger, at all then such errors are known as errors of omission and such errors have no effect on the Trial balance.
(ill) Posting to Wrong Account: When any entry is posted in wrong account, but on the correct side then it cannot be located easily by trial balance.
(iv) Errors of Amounts in Original Book: If wrong amount is written in the books of original entry it will have no effect on the accuracy of the trial balance.
(v) Compensating Errors: There are certain errors, whose effect is compensated by other errors are known as compensatory errors. The total of trial balance remains equal in such case.

The objectives of Trial Balance are as follows: (i) Ascertaining arithmetical accuracy: Trial balance act as a device to check the arithmetical accuracy of the accounting process culminating in the ledger accounts. If the Trial Balance agrees, it may be taken that arithmetical errors do not exist, even though this cannot be conclusively stated.
(ii) Summarize: To afford a summarised version of the position of each account and accounts in general. Scanning the Trial Balance enables one to know the assets that one possesses, the amounts that are owed to others and the amounts due from others, etc.
(iii) Facilitates preparation of financial statements: To act as a starting point for the preparation of the final accounts, viz., the Profit & Loss Account and the Balance Sheet. The final accounts are made on the basis of the trial balance. The various adjustments that are to be made can be made only after the Trial Balance is ready.

Trial Balance is a statement prepared with debit and credit balances of all accounts in ledger, to verify the arithmetical accuracy of the accounts. It is prepared after balancing all the accounts of ledger. There are two columns in a Trial Balance: debit and credit. While debit side includes all the debit balances, credit side includes all the credit balances of the accounts. It also helps in preparing financial statements, as it is a summarised version of the ledger. It is generally prepared on monthly or yearly basis.

Main objective of preparing a Trial Balance is to check the accuracy of the accounts. However, the equality of debits and credits of Trial Balance does not mean that there are absolutely no errors in the books of account. There may be number of errors which may remain undetected inspite of the agreement of a trial balance As such, it is true that "Trial Balance is not a conclusive proof of the accuracy of book of accounts." There are certain errors which do not affect the agreement of the Trial Balance. Such errors are also called limitations of Trial Balance. These are the following errors.
(i) Errors of Omission
(ii) Errors of Commission
(iii) Compensating errors
(iv) Errors of Principles
(v) Errors of posting in wrong account
Sometimes inspite of best efforts of an accountant, all the errors are not located and the Trial Balance does not tally. So, the Trial Balance has certain limitations.

Following one sided errors would cause difference in the trial balance-
(i) Partial Omission.
(ii) Wrong casting of subsidiary books
(iii) Posting wrong amount in ledger
(iv) Posting on wrong side of account
(v) Wrong Balance of account
Errors which will not be revealed in trial balance are as follows :
(i) Complete Omission.
(ii) Error of principle
(iii) Compensating errors
(iv) Recording wrong amount in Journal
(v) Posting amount in wrong account but on correct side.

Suspense Account may be defined as a temporary account to which the difference in trial balance has been put till the errors are located and rectified. For example: A payment received from an unidentified party is recorded as:
Bank A/c       Dr.
To Suspense A/c
While preparing Trial Balance, if an accountant is unable to detect the difference in the totals of the Trial Balance, he can put the difference in suspense account. If the debit side is short, the suspense account shall be debited by the amount of difference. If the credit side is short, then the difference shall be credited to the suspense account. Thus, with the help of the suspense account the trial balance will get balanced. As soon as the errors are detected, these are rectified by passing Journal entries. When all the errors leading to difference in the trial balance are located and rectified, the suspense account shall be closed automatically.

Suspense Account: Sometimes, errors come into notice after preparing the Trial Balance. When Trial Balance is prepared and accountant is unable to find errors affecting the agreement of the Trial Balance, he puts the difference in trial balance in a newly opened account, which is called Suspense Account.
Suspense Account is opened only when there is a difference in the Trial Balance, by placing the difference in this account. If the debit side of trial balance is more than the credit side, then difference is put on the credit side of suspense account. If the credit side of trial balance is more than the debit side then the difference is put on the debit side of suspense account. After opening this account, onesided errors are rectified by passing journal entry through suspense account. Posting of these entries is made in the suspense account. When all the errors leading to disagreement of the trial balance are located, the suspense account is automatically closed.