Question

Equation of the hour hand at 4 O’ clock is.

• A. $x - \sqrt { 3 } y = 0$
• B. $\sqrt { 3 } x - y = 0$
• C. $x + \sqrt { 3 } y = 0$
• D. $\sqrt { 3 } x + y = 0$

Answer 1

Answer: (C)

$x + \sqrt { 3 } y = 0$

Answer 2

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 $30 ^ { \circ }$angle in fourth quadrant. So the equation of hour hand is

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

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