TEM

Assertion. Fine structure of the objects can be observed by transmission electron microscope (TEM). Reason. Study of living cells cannot be done through TEM, because of high voltage, which is required to operate it, Kills the cells.

The sum of 'n' terms of an A.P is 715.If first term is incrased by 1, second term is increased by 3, third term is increased by 5 and so on k^(th) term is increased by k^(th) odd integer then sum of 'n' tems is 836 then value of (n/6) is

Two identical glass bulbs are interconnected by a thin tube of negligible volume. An ideal gas is filled in the bulbs at STP. One bulb is placed in a tub of melting ice and the other bulb is placed in a hot bath. The gas pressure in the bulbs becomes 1.5 times. Find the tem perature of the hot bath. Which bulb has more gas?

The sum of 20 terms of a series of which every even term is 2 xx the term before it,every odd term is 3 xx the term before it,the first tem being unity is ((2)/(7))(6^(10)-1) b.((3)/(7))(6^(10)-1) c.((3)/(5))(6^(10)-1) d.none of these

In a cylindrical container two pistons enclose gas in two compartments as shown in the figure. The pistons have negligible thickness and can move without friction. The sys- tem is originally in equilibrium. The outer piston is slowly moved out by 10 cm and the inner piston is found to move by 4 cm. Find the distance of the inner piston in equilibrium from the closed end of the cylinder if the outer piston is slowly moved out of the cylinder. Assume temperature of the gas to remain constant.

Consider ·an astronaut trapped in space, isolated from surrounding. He can reach his spacecraft if some velocity is gained by him somehow. Suddenly he realises that he has got a small pencil in his pocket. How can he acquire velocity (momentum) ? We take the system to consist of the astronaut and the pencil as shown in Fig. 4.4. We assign the positive direction of the x-axis to be the direction of throw. The gravitational force acts on the $Y5tem, which indeed is external force. However, this force is directed along the y-axis, it will not change momentum along x-axis. we· can thus apply the conservation of momentum to this system. What happens to the force exerted by the astronaut on the pencil while throwing it? m_(a) vecV_(ai) + m_(p)vecV _("pi") = m_(a) vecV _(af) + m_(p)vecV _(pf) 0 + 0 = M_(a)vecV_(af) + m_(p)vecV _(pf) vecV_(af) =-(m_(P)vec_(pf))/m_(a) The negative sign indicates that the astronaut moves in the direction opposite. to the direction of motion of the pencil.