Piyush Dixit MCA 4 years of teaching experience for Competitive Exams

Piyush Dixit Clock Chapter-1 12 10 9 2 3 4 8 7 5 6 "Even a Broken clock is right twice a day"

Clock is one of the most asked topic in any exam V There are approx 9-10 or even more different types of questions which can be asked in exam from this topic In this section we will deal with basic concepts of clock and then successively we will try to cover almost all the possible types of questions.

Look into History "Study of time keeping is known as Horology" Word Clock is derived from the Celtic words Clagan and Clocca which means Bell Mechanical Clock was invented in world near by end of 13th century.

12 10 Angle of hour hand in a minute: Since hour hand of clock takes 12 hours to complete the circle which is Of 360%. For one hour the angle made by hour hand of clock 3 8 4 7 6 will be 360 /12- 30 per hour And 30%/60- or 0.5"per minute

12 10 3 Angle of minute hand in a minute: 8 Since minute hand of clock takes 1 Hour or 60 minutes to complete full circle which is Of 360% So per minute rotation or angle made by minute hand 4 7 6 will be 360/60 6 per minute

12 Some Basic known Facts 10 2 9 3 1. In every hour, both the hands coincide once 2. When the two hands are at right angle, they are 15 8 4 7 6 minute spaces apart. This happens twice in every hour minute spaces apart. This happens once in every hour. of clock once in 12 hours. So the minute hand is twelve 3. When the hands are in opposite directions, they are 30 4. The hour hand moves around the whole circumference times faster than hour hand 5. In One minute, time gained by minute hand in comparison to hour hand is (6-0.5)-5(1/2) Degree per minute

Basic Properties: 12 1. The hands of a clock coincide: Means angle between them will be 0 22 times per Day 3 4 7

2. The hands of a clock in straight line but opposite in direction: Means angle between them will be 180 12 22 times per Day 2 3 4 7

3. The hands of a clock are at right Angles : Means angle between them will be 90 44 times per Day 12 10 2 9 3 8 4. 6

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Piyush Dixit

A Techie who is blend of Software Engineering as profession and Teaching as Passion.

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Ajay Dev Dev

a year ago

love you Ma'am and thank-you for this valuable video.....

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AJAY SHARMA

2 years ago

Very nice sir..... this topic was very confusing for me but after seeing this feeling comfortable.... thank you so much UNACADEMY....

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Piyush Dixit

2 years ago

Thanks :)

Harsh Singh

2 years ago

sir 5th point please explain some more

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Piyush Dixit

2 years ago

Since in one minute, minute hand of clock moves 360/6 = 6 degree and hour hand moves 360/12x6 = 0.5 degree so difference between both hand of clock is 6-0.5 which is 5.5 degree per minute or we can say that minute hand will gain this much. i hope your doubt is clear now :)
feel free to message for other doubts. Keep Learning :)

Harsh Singh

2 years ago

thanks sir????

Meera Vyas

2 years ago

This was indeed confusing. Thank you for explaining with simplicity

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Shilpa Jamadandi

2 years ago

tq u sir

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