Dr Vince’s Physics Advanced level Test: Grade XI, Chapter 1

မရုိးသားေသာနည္းမ်ားျဖင့္ အမွတ္မ်ားေအာင္ လုပ္ႏိုင္ေသာ္လည္း ပညာတတ္ မျဖစ္လာႏိုင္ပါ။

အႀကဳိးစားဆံုးေသာသူသည္သာ အေတာ္ဆံုးျဖစ္သည္။ အၿမဲတမ္းႀကဳိးစားေနသူသာ အၿမဲတမ္းအမွတ္မ်ားသည္။

Dr Vince’s Physics Advanced level Test: Grade XI, Chapter 1

Time allowed: 1 h; Answer ALL Questions: Pass ≥ 84 %, Distinction ≥ 96 %

(1) Do not use correction pen. (2) Answer as exactly as prescribed Text.

1.	Fill in the blanks.			[5 marks]
	(i)		____ is the energy transferred in any system where a force causes movement.
	(ii)		__________ transmits force from one point to the next.
	(iii)		A ____________ is an appliance that enables work to be done.
	(iv)		The Mechanical Advantage of a machine depends on the _________ present.
	(v)		_________ may be defined as the product of force applied and displacement
2.	Are the following statements True (or) False?			[5 marks]
	(i)	The lever generates a turning effect when a force is applied at the pivot.
	(ii)	In practice, output work always exceeds input work.
	(iii)	The strain is proportional to the stress.
	(iv)	One horse power is equal to 550 ft-lb.
	(v)	The MA is usually much less than VR.
3.	Define efficiency. Why it is always less than 100%?			[4 marks]
4.	A 40 kg girl runs up a stairs 10 m high. How much work has been done by her?			[4 marks]
5.	The rate of doing work of the first worker is three times that of the second worker. The working hour per day of the second worker is two and a half times that of the first worker. Who works more?			[4 marks]
6.	The elastic limit of a certain spring is 40 N. When 10 N load is applied, the spring extends 3 cm. Find the spring constant. What will happen to the spring when the load is removed?			[4 marks]
7.	(i) Can a lot of work be done only if a large power machine is used? (ii) A lever of efficiency 75 % overcomes a load of 32 kg when an effort is 16 N. Find the velocity ratio.			[8 marks]
8.	(i) Define elasticity. Draw the graph of strain vs stress. (ii) A 1000 W water pump is pumping up water from a well 40 m deep. How long will it take to pump 10 kg of water?			[8 marks]
9.	(i) What are simple machines? What do they do? (ii) With what speed can a 2 hp machine lift a 7460 g of load upward?			[8 marks]