# ICSE Physics 2021 Specimen Paper for Class-10 Solved

ICSE Physics 2021 Specimen Paper for Class-10 Solved on further reduced Syllabus. Specimen Paper of **Physics** for **ICSE** Class-10 is helpful for student appearing in 2021 exam of council. This paper content is based on further reduced syllabus as latest council guideline for 2021 exam. Visit official website CISCE for detail information about ICSE Board Class-10 Physics.

**ICSE Physics 2021 Specimen Paper for Class-10 Solved**

- Answers to this Paper must be written on the paper provided separates
- you will not be allowed to write during the first 15 minutes.This time is to be spent in reading the Question Paper.
- The time given at the head of this Paper is the time allowed for writing the answers
**.** - Attempt all the questions from Section I and any four questions from Section II.
- The intended marks for questions or parts of questions are given in brackets [ ].

**SECTION I (40 Marks)**

ICSE Physics 2021 Specimen Paper for Class-10 Solved on further reduced Syllabus

Attempt all questions from this Section

**Question 1:**

**(a)**

(i) Give an example of a non contact force which is always of attractive nature.

(ii) How does the magnitude of this non contact force on the two bodies depend on the distance of separation between them? **[2] **

**(b) **

(i) Name one factor that affects the lateral displacement of light as it passes through a rectangular glass slab.

(ii) Rajan exerts a force of 150 N in pulling a cart at a constant speed of 10 m/s. Calculate the power exerted. ** **

**(c) **

(i) Where is the centre of gravity of a uniform ring situated ?

(ii) “The position of the centre of gravity of a body remains unchanged even when the body is deformed.” State whether the statement is true or false. [2]

**(d)** A stone of mass ‘m’ is rotated in circular path with uniform speed by tying a strong string with the help of your hand. Answer the following questions.

(i) Is the stone moving with a uniform or variable speed ?

**(**ii**)** Is the stone moving with a uniform acceleration ? What is the effect of acceleration ? In which direction does the acceleration act ?

**(e)** What do you understand by the following statements: **[2]**

(i) The heat capacity of the body is 60 JK^{-1}.

(ii) The specific heat capacity of lead is 130 Jkg^{-1} K^{-1}.

**Question-2**

(a)

A uniform metre scale is balanced at 60 cm mark, when weights of 5 gf and 40 gf are suspended at 10 cm mark and 80 cm mark respectively. Calculate the weight of the metre scale.

(b) For which colour of white light, is the refractive index of a transparent medium (i) the least (ii) the most?

(c) Which colour of light travels fastest in any medium except air?

**(d)** What do you understand by the term lateral displacement ?

**(e)** State three factors which determine lateral displacement ?

**Question-3**

(a) What do you understand by the term resonance ? Give two conditions for producing resonance

(b) What do you understand by the term quality of sound ?

(c) An enemy plane is at a distance of 300 km from a radar. In how much lime the radar will be able to detect the plane ? Take velocity of radio waves as 3 × 10^{8} ms^{-1}.

(d) Arrange the α, β, or γ radiation in ascending order of their (i) ionizing powers, and (ii) penetrating powers.

(e) An atomic nucleus A is composed of 84 protons and 128 neutrons. The nucleus A emits an -particle and is transformed into a nucleus B. What is the composition of B?

**Question-4**

(a) A Cell of e.m.f. ε and internal resistance ? sends current 1.0 A when it is connected to an external resistance 1.9Ω. But it sends current 0.5 A when it is connected to an external resistance 3.9 Ω.Calculate the values of ε and ?.

(b) Calculate the effective resistance between the points A and B in the circuit shown in Figure

(c) A heater, rated 1000 W, is used to heat 1.5 kg of water at 40°C to its boiling point. Calculate the time in which the water starts to boil Specific heat capacity of water is 4200. J kg^{-10} C^{-1}.

(d)

The diagram in figure shows a radioactive source S placed in a thick lead walled container. The radiations given off are allowed to pass through a magnetic field. The magnetic field (shown as x) acts perpendicular to the plane of paper inwards. Arrows shows the paths of the radiation A, B and C.

(i)Name the radiations labelled A, B and C.

(ii)Explain clearly how you used the diagram to arrive at the answer in part(i).

**SECTION II (40 Marks)**

ICSE Physics 2021 Specimen Paper for Class-10 Solved on further reduced Syllabus

Attempt any four questions from this Section

**Question 5.**

**(a**)

(i) Derive a relationship between SI and C.G.S. unit of work. **[3]**

(ii) A force acts on a body and displaces it by a distance S in a direction at an angle θ with the direction of force. What should be the value of θ to get the maximum positive work?

**(b**)

(i) State two differences between “Heat Capacity” and “Specific Heat Capacity”.** [3]**

(ii) Give a mathematical relation between Heat Capacity and Specific Heat Capacity.

(c) Write the names of all the components of electromagnetic spectrum in the order of increasing frequency.

**Question-6**

**(a)**

(i) How is the transference of heat energy by radiation prevented in a calorimeter ? **[3]**

(ii) You have a choice of three metals A, B and C, of specific heat capacities 900 J kg^{-1} °C^{-1}, 380 / kg^{-1} °C^{-1} and 460 J kg^{-1} °C^{-1} respectively, to make a calorimeter. Which material will you select ? Justify your answer.

**(b)**

(i) Can the absolute refractive index of a medium be less than one ?

(ii) An observer stands at a certain distance away from a cliff and produces a loud sound. He hears the echo of the sound after 1.8s. Calculate the distance between the cliff and the observer if the velocity of sound in air is 340 ms. **[3]**

**(c) **

(i) Why does a bottle of soft drink cool faster when surrounded by ice cubes than by ice cold water, both at 0 °C ?

(ii) A certain amount of heat Q will warm lg of material X by 3 °C and 1 g of material Y by 4 °C. Which material has a higher specific heat capacity ? [3]

**Question-7**

A pair of scissors is used to cut a piece of a cloth by keeping it at a distance 8.0 cm from its rivet and applying an effort of 10 kgf by fingers at a distance 2.0 cm from the rivet.

(a) Find: (i) the mechanical advantage of scissors and (ii) the load offered by the cloth.

(b) How does the pair of scissors act: as a force multiplier or as a speed multiplier?

(c) Give two reasons why the efficiency of a single movable pulley system is not 100%.

**Question-8**

A man uses a crowbar of length 1.5 m to raise a load of 75kgf by putting a sharp edge below the bar at a distance 1 m from his hand.

(a) Draw a diagram of the arrangement showing the fulcrum (F), load (L) and effort (E) with their directions.

(b) State the kind of lever.

(c) Calculate: (i) load arm, (ii) effort arm, (iii) mechanical advantage, and (iv) the effort needed.

**Question-9**

(a)

A piece of iron of mass 2.0 kg has a thermal capacity of 966 J K^{-1}. Find

(i) Heat energy needed to warm it by 15^{o}C, and

(ii) Its specific heat capacity in S.I unit

(b)

Radioactivity is a nuclear phenomenon’. Comment on this statement.

(c)

**(c)** A battery of emf 12V and internal resistance 2Ω is connected with two resistors A and B of resistance 4Ω and 6Ω respectively joined in series.

Find

(i) Current in the circuit.

(ii) The terminal voltage of the cell.

(iii) The potential difference across 6Ω Resistor.

(iv) Electrical energy spent per minute in 4Ω Resistor.

**Question-10**

**(a)** Arrange α, β and γ rays in ascending order with respect to their:

(i) Penetrating power.

(ii) Ionising power.

(iii) Biological effect.

**(b)** An object AB is placed between O and F_{1} on the principal axis of converging lens as shown in the diagram.

Copy the diagram and by using three standard rays starting from point A, obtain an image of the object AB.

**(c)** An object is placed at a distance of 12 cm from a convex lens of focal length. 8 cm. Find:** [4]**

(i) the position of the image

(ii) nature of the image

**Solutions**

**Answer- 1:**

**(a)**

(i) Gravitation Force.

(ii) It varies inversely as the square of distance of separation between them i.e., as the distance between the two bodies increases, the magnitude of the force between them decreases

**(b)**

(i) The factors that affect the lateral displacement of a light as it passes through a rectangular glass slab are :

(1) **The thickness of the glass slab:** The lateral displacement increases with the increase in the thickness of the glass slab.

(2) **The angle of incidence:** It increases with the increase in the angle of incidence.

(3)** The refractive index of glass:** The wavelength of light used. (It is more for violet light than for the red light.) (any one)

(ii)

Given : Force = 150 N, Speed = 10 m/s.

Power = Force × Speed

= 150 × 10

= 1500 Watt.

**(c)**

(i) At the centre of the ring

(ii) False

**(d)**

**(i)** Uniform speed.

**(ii)** Yes, the stone is moving with uniform acceleration.

Effect of accelerated motion is it makes the body move in circular path. Acceleration acts at right angle to the radius of circle.

**(e)**

(i) The given body requires 60 J of heat energy to raise its temperature through 1K.

(ii) 1 kg of lead requires 130 J of heat energy to raise its temperature through 1K.

**Answer-2**

(a)

**Answer 1:
**

Let w be the mass of metre scale acting a mid point 50 cm

Clock wise moment = 40 × (80 – 60)

= 40 × 20 = 800 g f cm …….(i)

Anticlockwise moments

= 5 × (60 – 10) + w × (60 – 50)

(250 + 10 w) gf cm ……..(ii)

Anticlockwise moment = clock wise moment

250+ 10 w = 800

10 w= 800 -250 = 550

w = 550/10 = 55 gf

**(b)**

(i) The least for red colour and (ii) the most for violet colour.

**(c)** Red colour travels the fastest as its wavelength is the highest.

**(d) Lateral Displacement :** “The perpendicular shift in the path of the incident ray while emerging out of an optical slab is called Lateral Displacement.”

**(e) Factors :**

- Angle of incidence
- Thickness of optical slab
- Refractive index of optical material.
- Wavelength of light.

**Answer-3**

(a)

**Resonance :** “is a special case of forced vibrations. When the frequency of an externally applied periodic force on a body is equal to its natural frequency, the body readily begins to vibrate with an increased amplitude. This phenomenon is called resonance.”

**Two conditions of resonance :**

- The natural frequency of the given body (non-vibrating body) must be equal to (or its integral multiple) the frequency of the vibrating body.
- The vibrating body must have sufficient force, so as to. set the other body into vibrations.

(b) **Quality of sound :** “The notes of different instruments having

the same frequencies and same loudness are distinguished by this characteristics.” It is because different waveforms are produced by different musical instruments.

(c) d=300 t = ? v = 3 × 10^{8} ms^{-1}

t=2d/v = 2 × 300 × 1000m/3 ×10^{8} ms^{-1}

=0.002 s = 2 × 10^{-3 }s

(d)

Ionizing power of alpha radiation is maximum i.e., 10000 times of gamma radiation while beta particles have lesser ionizing power i.e., 100 times of gamma radiation and gamma radiation have least ionizing power.

Penetration power is least for alpha particle and maximum for gamma radiation

(e) The composition of B – 82 protons and 126 neutrons.

**Answer-4**

(a) In first case

I = 1 A, R = 1.9 ohm

ε = I(R + r) = 1(1.9+r)

ε = 1.9 + r————(1)

In second case

I = 0.5 A, R = 3.9 ohm

ε = I(R + r) = 0.5 (3.9 + r)

ε = 1.95 + 0.5r —————-(2)

From eq. (1) and (2),

1.9 + r = 1.95 + 0.5r

r = 0.05/0.5 = 0.1 ohm

Substituting value of r

ε = 1.9 + r = 1.9 + 0.1 = 2 V

(b)

(c)

**(d)**

(i ) Radiations labeled A, B and C are α, β, or γ respectively.

(ii) Radiation labeled A is gamma radiation because they have no charge and hence under action of magnetic field they go un deflected.

Radiation B is alpha radiation because its mass is large and it would be deflected less in comparison to beta radiation.

**Answer: 5**

**(a)**

(i) 1 J = 1 kg × 1 m^{2} × 1 s^{-2} = 10^{3} g × 10^{4} cm^{2} × 1 s^{-2} = 10^{7} g cm^{2} s^{-2} = 10^{7} erg

(ii) W = FS cos θ = FS (maximum) if cos θ = 1 or θ = 0°

(b)

(i)

The difference between the specif heat capacity and heat capacity is listed below.

Specific heat capacity |
Heat capacity |

Specific heat, C_{sp}, is the amount of heat required to change the heat content of exactly 1 gram of a material by exactly 1°C |
The heat capacity of a substance can be defined as the amount of heat required to change its temperature by one degree |

The formula of specific heat capacity is given by
Q = C m ?t where Q is the quantity of heat absorbed by a body, m is mass of the body, ?t is the rise in temperature and C is the specific heat capacity of a substance depending on the nature of the material of the substance. |
The formula for heat capacity is given by
Q=CΔT Where Q is the heat energy required to bring about a temperature change of ΔT and C is the heat capacity of the system under study. |

(ii) The relation is, heat capacity = specific heat x mass of substance.

**(c)**

Components of electromagnetic spectrum in order of increasing frequency :

Radio wave microwave infra-red visible ultra violet, X rays, Gama rays

→ 3 × 1o^{7} Hz 3 × 10^{11} HZ 7.5 × 10^{14} 3.75 × 10^{14} – 3 × 10^{16 }HZ 3 × 10^{19} HZ

**Answer-6**

**(a)**

(i) This is done by polishing the inner and outer surface of the copper

calorimeter and the space between the copper vessel and the insulating container is filled with some poor conductor like wood wool or glass wool.

(ii) A, as it will gain less energy in a given time.

**(b) **

(i) No.

(ii)

Given : v = 340 m/s, t = 1.8s

Distance= 2d

Speed= Dis/ Time

2d= v x t

d = v x t / 2

d = 340 x 1.8 / 2

= 306 m

(c)

i) Because 1 gm of ice at 0°C takes 336 J of heat energy from the drink to melt into water at 0°C. Thus drink loses an additional 336 J of heat energy for lg ice at 0°C than for 1 gm ice-cold water at 0°C. Therefore cooling produced by lg ice at 0°C is more than that by 1 gm water at 0°C.

(ii)

Specific heat capacity = Q /m Δ t

So material X has a higher specific heat capacity.

**Answer-7**

(a)

Effort arm = 2 cm

Load arm = 8.0 cm

Given effort =10 kgf

(i) MA = Effort arm/ load arm

= 2/8

= 0.25

(ii)

load = MA x effort

= 0.25 x 10

= 2.5 kgf

(b)

the pair of scissor act as speed multiplier because MA< 1

(c)

The efficiency of a single movable pulley system is not 100% this is because

(i)The friction of the pulley bearing is not zero ,

(ii)The weight of the pulley and string is not zero.

**Answer-8**

**Answer-9**

(a)

(i)

We know that heat energy needed to raise the temperature by 15^{o} is = heat capacity x change in temperature.

Heat energy required= 966 J K^{-1} x 15 K = 14490 J.

(ii)We know that specific heat capacity is = heat capacity/ mass of substance

So specific heat capacity is = 966 / 2=483 J kg^{-1 }K^{-1}.

(b)

Any physical changes (such as change in pressure and temperature) or chemical changes (such as excessive heating, freezing, action of strong electric and magnetic fields, chemical treatment, oxidation etc.) do not alter the rate of decay of the radioactive substance.

This clearly shows that the phenomenon of radioactivity cannot be due to the orbital electrons which could easily be affected by such changes. The radioactivity should therefore be the property of the nucleus. Thus radioactivity is a nuclear phenomenon.

(c)

**Answer-10**

**(a)**

(i) α < β < γ

(ii) γ < β < α

(iii) α < β < γ

**(b)** The figure is as shown.

Given u = – 12 cm,f= + 8 cm, v = ?, nature= ?

Using the lens formula we have

Or v = 24 cm, Image will be real and inverted.

–: End of ICSE Physics 2021 Specimen paper : —

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