MCQ
Equation of the hour hand at $4$ O’ clock is
  • A
    $x - \sqrt 3 \;y = 0$
  • B
    $\sqrt 3 \;x - y = 0$
  • $x + \sqrt 3 \;y = 0$
  • D
    $\sqrt 3 \;x + y = 0$

Answer

Correct option: C.
$x + \sqrt 3 \;y = 0$
c
(c) Since the hour, minute and second hands always pass through origin because one end of these hands is always at origin. Now at $4$ O’ clock, the hour hand makes ${30^o}$angle in fourth quadrant. So the equation of hour hand is

$y = mx \Rightarrow y = - \frac{1}{{\sqrt 3 }}x$

$ \Rightarrow x + \sqrt 3 y = 0$.

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