A spring of force constant k is stretched by a length x. The work done in stretching it further by the same length x is: MCQ with Answer and Explanation

Explanation:
A CRO uses an electron beam sweeping across a phosphorescent screen to create a visible graph. It is fundamentally a voltage-measuring instrument. The vertical deflection is directly proportional to the applied voltage, and the horizontal deflection is controlled by a time-base generator, allowing it to display voltage waveforms over time.

Explanation:
In uniform circular motion, speed is constant but velocity direction changes continuously, producing centripetal acceleration. Magnitude a = v²/r, direction always towards the center of the circle. This acceleration changes velocity direction without altering speed. Tangential acceleration would change speed, but here speed is constant. Formula derivation: From vector analysis of velocity change over small time interval. Exam tip: Remember 'centripetal' means 'center-seeking'; this concept is fundamental for rotational dynamics questions in competitive exams.

Explanation:
(1/2)ⁿ = 1/32 ⇒ 2ⁿ = 32 ⇒ n = 5 half-lives. Exponential decay calculation. Memory aid: '1/2ⁿ remaining; 1/32 = 1/2⁵ ⇒ 5 half-lives'. Radioactivity arithmetic frequently tested in competitive exams.