CBSE Class 4 Maths Carts And Wheels Worksheet Set 01

Ques.1 Which will swept a bigger circle - a door or a small window?
Answer: A door.
In simple words: A larger object creates a bigger circle when opened completely.
Exam Tip: Size of the swept circle depends directly on the radius or length of the moving object.

Ques.2 To make the top spin well, where will you make the hole?
Answer: At the center.
In simple words: The hole must be exactly at the center so the top balances and spins smoothly.

Exam Tip: A top or wheel must always have its axis of rotation passing through its geometric center.

Ques.3 Give the answers of following: -
If all the inner circles have equal radius = 6 cm.
a) Length of BC = 12 Cm.
b) Length of FG = 12 Cm.
c) Length of EG = 18 Cm.
d) Length of AD = 24 Cm.
Answer:
a) BC is a diameter formed by two radii joined end-to-end, so length = \(6 + 6 = 12\) Cm.
b) FG is also a diameter passing through the center, so length = \(6 + 6 = 12\) Cm.
c) EG spans across three radii from E to G, so length = \(6 + 6 + 6 = 18\) Cm.
d) AD spans across four radii from A to D, so length = \(6 + 6 + 6 + 6 = 24\) Cm.
In simple words: Add the given radius for each part of the line segment across the circles.

Exam Tip: Diameter is always double the radius (\(\text{Diameter} = 2 \times \text{radius}\)).

Ques.4 If OC = 5 Cm and separation between the circles is equal = 7 Cm, find:-
a) Length of CD = 10 Cm.
b) Length of BE = 24 Cm.
c) Length of BO = 12 Cm.
d) Length of AF = 38 Cm.
e) Length of AE = 31 Cm.
Answer:
a) CD is the diameter of the second circle. Radius OC = 5 Cm, so CD = \(2 \times 5 = 10\) Cm.
b) BE spans across the outer circle including gaps and inner diameters. Detailed calculation gives 24 Cm.
c) BO consists of radius OC plus the separation gap, so length = \(5 + 7 = 12\) Cm.
d) AF spans the entire outermost structure, calculating to 38 Cm.
e) AE spans across the inner regions to point E, calculating to 31 Cm.
In simple words: Carefully add up each segment and gap length as shown in the concentric circles diagram.

Exam Tip: Always double check whether the segment asks for a radius or a full diameter.

Ques.5 Write four things which can be used to trace circle?
Answer: Bangle, coin, glass, plate.
In simple words: Any circular object can be used as a stencil to trace a circle.

Exam Tip: Memorize common round household objects for exam questions on circle tracing.

Ques.6 If two goats are tied to a pole in a ground. Which goat will trace bigger circle if the length of rope of second goat is greater?
Answer: Second goat.
In simple words: The goat with the longer rope can walk further away from the pole, tracing a bigger circle.

Exam Tip: The length of the rope acts as the radius of the circle.

Ques.7 Solve these:-
a) \(4 \times 2\) Cm = 8 Cm.
b) \(8 \times 7.5\) Cm = 60.0 Cm.
Answer:
a) \(4 \times 2 = 8\) Cm.
b) \(8 \times 7.5 = 60.0\) Cm.
In simple words: Multiply the given numbers directly with the unit centimeter.

Exam Tip: Keep the decimal point aligned properly when multiplying by decimals like 7.5.

Ques.8 Solve these:-
1. radius = 4cm, diameter = 8 cm.
2. radius = 6cm, diameter = 12 cm.
Answer:
1. Diameter = \(2 \times \text{radius} = 2 \times 4 = 8\) cm.
2. Diameter = \(2 \times \text{radius} = 2 \times 6 = 12\) cm.
In simple words: To find the diameter, multiply the radius by 2.

Exam Tip: Formula to remember: \(d = 2r\).

Ques.9 Look at the picture and answer the following:-
1. The centre of the small circle O.
2. The name of a smaller radius and its length OA and 4 cm.
3. The length of a large radius 5 cm.
4. Which is bigger:
a. OA
b. OB
Answer: (b) OB
OB is the radius of the larger outer circle (5 cm), whereas OA is the radius of the smaller inner circle (4 cm).
In simple words: The outer circle is bigger, so its radius OB is longer than OA.

Exam Tip: Compare radii by looking at which circle they belong to in concentric circle diagrams.

Topic: Carts and Wheels 

Competency :-Understanding Basic Concepts

1. Trace circles of different sizes using bangles, coins, bottle caps and such other circular objects.

Colour the smallest circle in red and the biggest circle in green.