Explanation:

Duties of Karta
Maintenance
All the members of the Hindu Joint Family whether coparcenary or not have a right to maintenance. It is the duty of the Karta to maintain all the members. No member of the family can be deprived of the right to maintenance and if they are they can challenge it before the court and claim their right and arrears of maintenance.

Marriage
Karta has a duty to engage the unmarried members of the family in wedlock especially of daughters as their marriage is considered to be sacrosanct in Hindu law. In the case of Chandra Kishore v. Nanak Chand, it was held that It is the duty of the Karta to bear all the expenses of the marriage from the joint family funds, or if in a case the expenses are incurred by some other sources he’ll have to reimburse them when asked. 

Render accounts
In Hindu law, a Karta is not under the obligation to maintain the family business account, but he is under the obligation to render the accounts if any coparceners demand it at the time of partition. He can be held liable for any misappropriation or fraud. 

Representation
The senior-most member of the family commonly known as Karta is the one who represents the Joint Hindu Family. The family does not have a corporate existence, it acts through its Karta. The Karta is bound to perform functions like paying all the taxes, dues etc on behalf of his family. Karta can also be sued on behalf of his family. 

Liabilities of Karta
Liability to maintain
The Karta of the Hindu Joint Family is liable to maintain all the members of the joint family. All the members of the Joint Hindu Family have a right to maintenance and residence. If the Karta is unable to maintain them he can be sued for the same and the member can claim their arrears of maintenance.

Liability to spend reasonably
The Karta also has the power to spend funds from the joint family account. But such power is limited to some restrictions such as the Karta cannot use the funds for unlawful purposes and also he should spend it wisely. If any of the coparceners is not satisfied with the spending made by the Karta he/she can file a suit against the Karta and discover the truth. 

Liability not to alienate property
The Karta is allowed to alienate the Joint Hindu Family Property only in certain cases such as legal necessity, the benefit of the estate, in case of indispensable duties. Other than this the Karta is not allowed to alienate the Joint Family Property. If he wrongfully alienates the property then the coparceners have a right to challenge the alienation.

Liability not to start a new business
The Karta of the family is under the obligation not to start a new business without the prior consent/permission of coparceners of the Joint Hindu Family. Once the coparceners expressly or impliedly have given their consent, the Karta can start a new business. 

Liability to render accounts
Until the family remains joint, the Karta has no obligation to maintain the accounts. But as soon as the partition takes place the Karta is under an obligation to render the accounts of Joint Family Property