A person of weight $$70 \mathrm{~kg}$$ wants to loose $$7 \mathrm{~kg}$$ by going up and down $$12 \mathrm{~m}$$ high stairs. Assume he burns twice as much fat while going up than going down. If $$1 \mathrm{~kg}$$ of fat is burnt on expending 9000 k-cal. How many times must he go up and down to reduce his $$7 \mathrm{~kg}$$ weight?
(Take $$g=10 \mathrm{~ms}^{-2}$$)
The current gain of a transistor in common emitter mode is 49. The change in collector current and emitter current corresponding to change in base current by $$5.0 \mu \mathrm{A}$$, will be
A cylindrical conductor AB of non-uniform area of cross-section carries a current of 5A. The radius of the conductor at one end A is 0.5 cm. The current density at the other end of the conductor is half of the value at A. The radius of the conductor at the end B is nearly
One mole of an ideal diatomic gas undergoes transition from A to B along a path AB as shown below.
The change in internal energy of the gas during the transition is