Class 6 - Mathematics : Understanding Elementary
Exercise : 5.2
Top Block 1
NCERT Solutions Class 6 Mathematics Understanding Elementary Ex 5.2
Question: 1.What fraction of a clockwise revolution does the hour hand of a clock turn through, when it goes from
(a) 3 to 9,
(b) 4 to 7,
(c) 7 to 10,
(d) 12 to 9,
(e) 1 to 10,
(f) 6 to 3
Answer :
(a) ½ or two right angles
(b) ¼ or oneright angle
(c) ¼ or one right angle
(d) ¾ or three right angles.
(e) ¾ or three right angles.
(f) ¾ or three right angles.
Question: 2.Where will the hand of a clock stop if it:
(a)starts at 12 and make ½ of a revolution, clockwise?
(b)starts at 2 and makes ½ of a revolution, clockwise?
(c)starts at 5 and makes ¼ of a revolution, clockwise?
(d)starts at 5 and makes ¾ of a revolution, clockwise?
Answer :
(a) At 6,
(b) At 8,
(c) At 8,
(d) At 2
Question: 3.Which direction will you face if you start facing:
(b)East and make 1½ of a revolution clockwise?
(c)West and makes ¾ of a revolution, clockwise?
(d)South and make one full revolution?
(Should we specify clockwise or anti-clockwise for this last? Why not?)
Answer :
(a) West, (b) West , (c) North, (d) South
(For answer (d), it is immaterial whether we turn clockwise or anticlockwise, because one full revolution will bring us back to the original position)
Question: 4.What part of a revolution have you turned through if you stand facing:
(a)East and turn clockwise to face north?
(b)South and turn clockwise to fase east?
(c)West and turn clockwise to face east?
Answer :
(a) ¾
(b) ¾
(c) ½
Question: 5.Find the number of right angles turned through by the hour hand of a clock when it goes from:
(a) 3 to 6, (b) 2 to 8, (c) 5 to 11, (d) 10 to 1, (e) 12 to 9, (f) 12 to 6
Answer :
(a) One right angle
(b) Two right angles
(c) Two right angles
(d) One right angle
(e) Three right angles
(f) Two right angles
Mddle block 1
Question: 6.How many right angles do you make if you start facing:
(a)South and turn clockwise to west?
(b)North and turn anti-clockwise to east?
(c)West and turn to west?
(d)South and turn to north?
Answer :
(a) One right angle
(b) Three right angles
(c) Four right angles
(d) Two right angles
Question: 7. Where will the hour hand of a clock stop if it starts:
(a)from 6 and turns through 1 right angle?
(b)from 8 and turns through 2 right angles?
(c)from 10 and turns through 3 right angles?
(d)from 7 and turns through 2 straight angles?
Answer :
(a) At 9,
(b) At 2,
(c) At 7,
(d) At 7