I'm scoring around 205 marks. Can I expect selection??? Others are requested to put up their marks. 2 questions are wrong in paper. Q.36,56 q.53 answer is B Q.64 answer is C
When the answer key of astronomy will be declared? I expect around 30 marks.
Q.71 answer should be B. Q.56 None of them are correct. Solution: Ans.56: Every time it bounces, it reaches 80% of its height i.e. it loses 20% of its energy. After 4 bounces it will reach a height of (0.8)^4= 0.4096 meters From law of conservation of energy, initial energy mgh= m*10*1=10m Joules Final energy mgh'= m*10*0.4096 = 4.096*m Joules Loss= 5.904*m Joules Q=m*c*(change in temperature), where c is specific heat,given as 0.1 cal/g/Celsius => c=0.4182 Joules per gram per degree Celsius
5.904*m= m*0.4182*t => t= 5.904/0.4182= 14.117 degree Celsius But none of the option is 14.117 degree Celsius
please publish correct key by 8 pm
ReplyDeletewhy 3rd question is changed in resostart level 2 class -9.I demand
ReplyDeletePlease also publish jso 's question paper
ReplyDeleteI'm scoring around 205 marks. Can I expect selection??? Others are requested to put up their marks.
ReplyDelete2 questions are wrong in paper. Q.36,56
q.53 answer is B
Q.64 answer is C
When the answer key of astronomy will be declared? I expect around 30 marks.
Around 155
DeleteQ.71 answer should be B.
ReplyDeleteQ.56 None of them are correct. Solution:
Ans.56: Every time it bounces, it reaches 80% of its height i.e. it loses 20% of its energy.
After 4 bounces it will reach a height of (0.8)^4= 0.4096 meters
From law of conservation of energy,
initial energy mgh= m*10*1=10m Joules
Final energy mgh'= m*10*0.4096 = 4.096*m Joules
Loss= 5.904*m Joules
Q=m*c*(change in temperature), where c is specific heat,given as 0.1 cal/g/Celsius
=> c=0.4182 Joules per gram per degree Celsius
5.904*m= m*0.4182*t
=> t= 5.904/0.4182= 14.117 degree Celsius
But none of the option is 14.117 degree Celsius
make all the quantities in si units and u will get 0.014
DeleteQuestion No. 53
ReplyDeleteAnswer is 80 degree but none of the option is 80.
its 90
ReplyDelete