(a) State four main causes of providing depreciation.

(b) A Company purchased a machinery for Rs. 50,000 on 1st July 1988. Another machinery costing Rs. 10,000 was purchased on 1st September, 1989. On 31st Dec. 1990, the machinery purchased in 1988 was sold at a loss of Rs. 5,000. The company charges depreciation at the rate of 15% per annum on diminishing balance method. Accounts are closed on 31st Dec. every year.

Prepare Machinery account for 3 years.