List of top Questions asked in CBSE Class X

The table below shows the daily expenditure on food of 25 households in a locality

Daily expenditure (in Rs)	100 - 150	150 - 200	200 - 250	250 - 300	300 - 350
Number of households	4	5	12	2	2

Find the mean daily expenditure on food by a suitable method.

Do you think there are also parents like Mrs. Pumphrey?

Explain the following terms with one example each.
(a) Corrosion
(b) Rancidity

The following frequency distribution gives the monthly consumption of electricity of 68 consumers of a locality. Find the median, mean and mode of the data and compare them

Monthly consumption (in units)	Number of consumers
65 - 85	4
85 - 105	5
105 - 125	13
125 - 145	20
145 - 165	14
165 - 185	8
185 - 205	4

How did Mandela’s understanding of freedom change with age and experience?

A ladder has rungs 25 cm apart. (see Fig. 5.7). The rungs decrease uniformly in length from 45 cm at the bottom to 25 cm at the top. If the top and the bottom rungs are \(2\frac 12\) m apart, what is the length of the wood required for the rungs?

In a retail market, fruit vendors were selling mangoes kept in packing boxes. These boxes contained varying number of mangoes. The following was the distribution of mangoes according to the number of boxes.

Number of heartbeats per minute	50-52	53-55	56-58	59-61	62-64
Number of boxs	15	110	135	115	25

Find the mean number of mangoes kept in a packing box. Which method of finding the mean did you choose?

The angle of elevation of the top of a building from the foot of the tower is 30° and the angle of elevation of the top of the tower from the foot of the building is 60°. If the tower is 50 m high, find the height of the building.

Light enters from air to glass having refractive index 1.50. What is the speed of light in the glass? The speed of light in vacuum is 3 × 10⁸ m s⁻¹.

Was Anne right when she said that the world would not be interested in the musings of a thirteen-year-old girl?

An object of size 7.0 cm is placed at 27 cm in front of a concave mirror of focal length 18 cm. At what distance from the mirror should a screen be placed, so that a sharp focused image can be obtained? Find the size and the nature of the image.

Find the focal length of a convex mirror whose radius of curvature is 32 cm.

A student noted the number of cars passing through a spot on a road for 100 periods each of 3 minutes and summarised it in the table given below. Find the mode of the data :

Number of cars	0 - 10	10 - 20	20 - 30	30 - 40	40 - 50	50 - 60	60 -70	70 - 80
Frequency	7	14	13	12	20	11	15	8

A ray of light travelling in air enters obliquely into water. Does the light ray bend towards the normal or away from the normal? Why?

Bholi’s real name is Sulekha. We are told this right at the beginning. But only in the last but one paragraph of the story is Bholi called Sulekha again. Why do you think she is called Sulekha at that point in the story?

Solve 2x + 3y = 11 and 2x – 4y = – 24 and hence find the value of ‘m’ for which y = mx + 3.

A vertical pole of length 6 m casts a shadow 4 m long on the ground and at the same time a tower casts a shadow 28 m long. Find the height of the tower.

Explain the following.

Why is the tungsten used almost exclusively for filament of electric lamps?
Why are the conductors of electric heating devices, such as bread-toasters and electric irons, made of an alloy rather than a pure metal?
Why is the series arrangement not used for domestic circuits?
How does the resistance of a wire vary with its area of cross-section?
Why are copper and aluminium wires usually employed for electricity transmission?

Why does not Anil hand the thief over to the police? Do you think most people would have done so? In what ways is Anil different from such employers?

Why do we apply paint on iron articles?

The far point of a myopic person is 80 cm in front of the eye. What is the nature and power of the lens required to correct the problem?

A Gulab jamun, contains sugar syrup up to about 30% of its volume. Find approximately how much syrup would be found in 45 gulab jamuns, each shaped like a cylinder with two hemispherical ends with length 5 cm and diameter 2.8 cm (see the given figure). [Use \(\pi=\frac{22}{ 7}\)]

An umbrella has 8 ribs which are equally spaced (see Fig. 11.10). Assuming umbrella to be a flat circle of radius 45 cm, find the area between the two consecutive ribs of the umbrella.

Prove the following identities, where the angles involved are acute angles for which the expressions are defined:\(\frac{(\text{1 + tan² A})}{(\text{1 + cot² A})} = (\frac{\text{1 - tan A }}{\text{ 1 - cot A}})^²= \text{tan² A}\)

Draw the structure of a neuron and explain its function.