Clock

Clock:

 

Hour Hand and Minute Hand:

A clock has two hands, the smaller one is called the hour hand or short hand while the larger one is called minute hand or long hand.
 
In a minute, the hour hand moves 0.5 degree and minute hand moves by 6 degree.
 
In Each hour the minute hand covers more distance of 55 minutes in comparison to the hour hand.
 
Too Fast and Too Slow : 
If a watch or a clock indicates 9.15, when the correct time is 9, it is said to be 15 minutes too fast.
On the other hand, if it indicates 6.45, when the correct time is 7, it is said to be 15 minutes too slow.
 
Note:
  • If the angle between Minute hand and hour hand is 0º then they are 0 minute apart. (Hands are in straight line and together)
  • If the angle between Minute hand and hour hand is 90º then they are 15 minutes apart. (Hands are perpendicular to each other)
  • If the angle between Minute hand and hour hand is 180º then they are 30 minute apart. (Hands are in straight line but not together)
 

Examples:

Example 1:
The reflex angle between the hands of a clock at 10.25 is:
a) 180º
b) 192.5º
c) 195º
d) 197.5º
Solution:
 
Example 2:
At what time between 5.30 and 6 will the hands of a clock be at right angles?
a) 43*(5/11) min past 5
b) 43*(7/11) min past 5
c) 40 min past 5
d) 45 min past 5
Solution:
 
Example 3:
At what time between 7 and 8 o'clock will the hands of a clock be in the same straight line but, not together?
a) 5 min past 7
b) 5*(2/11) min past 7
c) 5*(3/11) min past 7
d) 5*(5/11) min past 7
Solution:
 
Example 4:
A watch which gains uniformly is 2 minutes low at noon on Monday and is 4 min. 48 sec fast at 2 p.m. on the following Monday. When was it correct?
a) 2 p.m. on Tuesday
b) 2 p.m. on Wednesday
c) 3 p.m. on Thursday
d) 1 p.m. on Friday
Solution:

Important Points: