If 20% of a radiactive element decays in 10 days, then amount of original material left after 30 days is (approx)
Options
(a) 78% (b) 62% (c) 51% (d) 48%
Correct Answer:
51%
During mean life of a radioactive element, the fraction that disintegrates is
Options
(a) e (b) 1/e (c) (e-1)/e (d) e/(e-1)
Correct Answer:
(e-1)/e
Explanation:
No explanation available. Be the first to write […]
A student performs an experiment to determine the Young’s modulus of a wire, exactly 2 m long, by Searle’s method. In a particular reading, the student measures the extension in the length of the wire […]
If longitudinal strain for a wire is 0.03 and its poisson’s ratio is 0.5, then its lateral strain is
Options
(a) 0.003 (b) 0.0075 (c) 0.015 (d) 0.4
Correct Answer:
0.015
Explanation:
No […]
A mass of 2.0 kg is put on a flat plan attached to a vertical spring fixed on the ground as shown in the figure. The mass of the spring and the pan is negligible. […]
A particle executing SHM with amplitude of 0.1 m. At a certain instant, when its displacement is 0.02 m, its acceleration is 0.5 m/s². The maximum velocity of particle is (in m/s)
Options
If a gymnast, sitting on a rotating stool with his arms outstretched, suddenly lower his hands, then
Options
(a) The angular velocity decreases (b) His moment of inertia decreases (c) The angular velocity […]
A small part of the rim of a fly wheel breaks off while it is rotating at a constant angular speed. Then its radius of gyration will
Options
(a) Increase (b) Decrease (c) Remain […]
A body is thrown upward from ground covers equal distances in 4th and 7th second. With what initial velocity the body was projected?
Options
(a) 20 m/s (b) 50 m/s (c) 30 m/s (d) 10 […]
Two balls are dropped from same height at 1 second interval of time. The seperation between the two balls after 3 second of the drop of the 1st ball is
Options
(a) 50 […]
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