An object is moving in a circular path with constant speed. Which of the following remains constant?
A. Velocity
B. Acceleration
C. Linear momentum
D. Kinetic energy
Answer: Option D
Solution (By JKSSB Mock Tests)
Speed constant implies magnitude of velocity constant, so kinetic energy (½mv²) is constant. Velocity changes due to direction change. Acceleration (centripetal) is directed towards centre, changes direction. Linear momentum vector changes. So only kinetic energy remains constant.
Explanation:
Electrical resistance (R) is Voltage/Current. Voltage (V) is Work/Charge. Work is [ML^2T^-2] and Charge is [AT]. So, V = [ML^2T^-3A^-1]. Therefore, R = V/A = [ML^2T^-3A^-2]. Memorizing the dimensional formula for resistance is highly recommended for competitive exams.
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