Complete ICSE Class X Physics 2023 question paper with accurate, step-by-step solutions.
(Attempt all questions from this section)
Clockwise moment produced by a force about a fulcrum is considered to be:
(b) Negative
Explanation:
If the effect on the body is to turn it clockwise, moment of force is called the clockwise moment and it is taken as negative, while if the effect on the body is to turn it anticlockwise, moment of force is called the anticlockwise moment and it is taken as positive.
When the speed of a moving object is doubled, then its kinetic energy:
(d) becomes four times
Explanation:
According to the formula:
K=\frac{1}{2}mv^2
Hence, when speed (v) is doubled, the kinetic energy increases by 4 times.
The energy conversion in a washing machine is from ……………
(b) electrical to mechanical
Explanation: In a washing machine, electrical energy changes into mechanical energy.
Which of the following radiations suffer maximum deflection in a magnetic field?
(b) Beta radiations
Explanation: Beta radiations suffer maximum deflection in a magnetic field due toits lighter mass.
Speed of blue light in water is:
(c) more than violet light
Explanation:
Speed of violet light is minimum and speed of red light is maximum. Hence, speed of blue light in water is more than violet light.
A concave lens produces only …………… image.
(c) virtual, diminished
Explanation: A concave lens always forms a virtual and diminished image.
When a body vibrates under a periodic force, the vibrations of the body are always:
(c) forced vibrations
Explanation:
When a body vibrates under a periodic force, the vibrations of the body are always forced vibration.
Two notes are produced from two different musical instruments, such that they have same loudness and same pitch. The produced notes differ in their:
(a) Waveform
Explanation:
Different instruments produce different subsidiary notes. A note played on piano has a large number of subsidiary notes, while the same note played on violin does not contain so many subsidiary notes. Hence, they have different waveforms.
When a current I flows through a wire of resistance R for time t then the electrical energy produced is given by:
(a) I2Rt
Choose the correct relation for e.m.f. (ε) and terminal voltage V:
(c) V < ε [when the cell is in use]
Explanation:
When a cell is used to send current to an external circuit, its terminal voltage V is less than its e.m.f. Hence, terminal voltage < e.m.f.
If the strength of the current flowing through a wire is increased, the strength of the magnetic field produced by it:
(b) increases
Specific latent heat of a substance:
(c) depends on the material
Specific heat capacity of a substance X is 1900 J kg−1 °C−1 means:
(b) 1 kg of substance X absorbs 1900 J heat for 1°C rise in temperature
When a ray of light travels normal to the given surface, then the angle of refraction is:
(c) 0°
Explanation:
The ray of light incident normally on a plane glass slab passes undeviated. Thus, if angle of incidence ∠i = 0°, then the angle of refraction ∠r = 0°.
Small air bubbles rising up a fish tank appear silvery when viewed from some particular angle is due to the:
(d) total internal reflection
Explanation:
Small air bubbles rising up a fish tank appear silvery when viewed from some particular angle because of the phenomenon of total internal reflection.
(a) When does the nucleus of an atom tend to become radioactive?
(b) Name a single pulley in which displacement of load and effort is not the same.
(c) State one advantage of this pulley.
(a) The nucleus of an atom becomes radioactive when number of neutrons in the nucleus exceeds the number of protons in it.
(b) Single movable pulley.
(c) Advantage of this type of pulley is that we can lift a heavier load with a small effort.
(a) What is the position of centre of gravity of a triangular lamina?
(b) When this triangular lamina is suspended freely from any one vertex, what is the moment of force produced by its own weight in its rest position?
(a) The centre of gravity for a triangular lamina is at the point of intersection of the medians.
(b) When the triangular lamina is suspended freely from any one vertex, the moment of force produced by its own weight in its rest position is zero. This is because the centre of gravity is at the point where its medians intersect and the triangle is in rotational equilibrium.
The diagram shows wheel O pivoted at point A. Three equal forces F1, F2 and F3 act at point B on the wheel.
(a) Which force will produce maximum moment about A?
(b) Give a reason for your answer in (a).
(a) Force F1 produces the maximum moment.
(b) Moment of force = force × perpendicular distance from the point of application of the force to the pivot point.
Since the three forces are equal, the moment depends on the perpendicular distance.
The perpendicular distance from the line of action of F1 to A equals the diameter of the wheel and is greater than for F2 and F3.
(a) What should be the angle between the direction of force and the direction of displacement, for work to be negative?
(b) Name the physical quantity obtained using the formula \frac{U}{h}, where U is the potential energy and h is the height.
(a) 180°
(b) As U=mgh, therefore \frac{U}{h} = mg. The physical quantity obtained is the weight of the object.
Calculate the power spent by a crane while lifting a load of mass 2000 kg, at velocity of 1.5 m s−1. (g = 10 m s−2).
mass (m) = 2000 kg
velocity (v) = 1.5 ms-1
weight or downward force = mg = 2000 x 10 = 20,000 N
From formula, Power = F × v
P = 20,000 × 1.5 = 30,000 W = 30 kW
Hence, power spent by the crane = 30 kW.
A metal foot ruler is held at the edge of a table. It is pressed at its free end and then released. It vibrates.
(a) Name the vibrations produced.
(b) State one way to increase the frequency of these vibrations.
(a) The vibrations produced are known as damped vibrations.
(b) Place the ruler partially off the table so that a shorter length is free to vibrate. The shorter the length of the ruler, the higher the frequency of its natural vibrations.
‘A geyser is rated 240 W – 220 V’. Explain the meaning of this statement.
It means that if the geyser is operated on a 220 V supply, the electric power consumed by it is 240 W, i.e. 240 J of electric energy is consumed by the geyser in 1 s.
(a) Is it possible for a concave lens to form an image of size two times that of the object? Write Yes or No.
(b) What will happen to the focal length of the lens if a part of the lens is covered with an opaque paper?
(a) No.
(b) The focal length of the lens will not change.
Explanation: The focal length is determined by the shape and refractive index of the lens. Covering a portion with opaque paper does not alter these properties.
(a) Which electrical component protects the electric circuit in case of excess current and which can also be used as a switch?
(b) Name the wire to which this electrical component is connected in an electric circuit.
(a) Miniature circuit breaker (MCB) protects the electric circuit in case of excess current and can also be used as a switch.
(b) The MCB is always connected in series with the live wire in the household circuit.
A copper conductor is placed over two stretched copper wires whose ends are connected to a D.C. supply as shown in the diagram.
(a) What should be the magnetic poles at the points A and B lying on either side of the conductor to experience the force in the upward direction?
(b) Name the law used to find these polarities.
(a) The magnetic poles at A and B should be of opposite polarity. If A is North, B should be South and vice versa.
(b) Fleming’s left hand rule can be used to find these polarities.
Thermal capacities of substances A and B are same. If mass of A is more than mass of B then:
(a) Which substance will have more specific heat capacity?
(b) Which substance will show greater rise in temperature if the same amount of heat is supplied to both?
(a) B will have more specific heat capacity.
Explanation:
Specific heat capacity, c = Heat capacity of body, C′ / mass of body, m. Therefore, c ∝ 1/m. Specific heat capacity of B will be more as its mass is less.
(b) Both substances will show equal rise in temperature as their thermal capacities are the same.
How is the radioactivity of a radio isotope affected if it undergoes a chemical change? Give a reason for your answer.
The radioactivity of a radioactive isotope is not affected by chemical changes.
Reason: This is because radioactivity is a nuclear phenomenon specifically related to the stability of the isotope’s nucleus, while chemical changes involve the rearrangement of electrons and the formation or breaking of chemical bonds.
(Attempt any four questions)
The diagram below shows the ray OP travelling through an equilateral prism of a certain material.
(a) Calculate the value of i2, if the angle of deviation is 43°.
(b) What is the ray QS called?
(a) Given, angle of prism (A) = 60° for an equilateral prism.
angle of incidence (i1) = 65°
Angle of deviation (δ) = 43°
𝑒 = i2 = ?
From formula,
Angle of deviation (δ) = 𝑖 + 𝑒 − 𝐴
Substituting the values we get:
43 = 65 + i2 – 60°
i2 = 43 – 5 = 38°
Hence, i2 = 38°
(b) Emergent ray
Copy the diagram given below and complete the path of the light ray PQ, as it emerges out of the prism by marking necessary angles. The critical angle of glass is 42°.
Below is the completed diagram showing the path of the light ray till it emerges out of the prism with all angles marked:
The diagram below shows two parallel rays A (Orange) & B (Blue) incident from air, on air-glass boundary.
(a) Copy and complete the path of the rays A and B.
(b) How do the speeds of these rays differ in glass?(c) Are the two refracted rays in glass parallel? Give a reason.
(a) Ray B (Blue) bends more than ray A (Orange), as shown in the diagram.
(b) In glass, the speed of orange ray A is more than that of blue ray B.
(c) No, the two refracted rays are not parallel.
Explanation:
Orange light has a greater speed in glass and bends less, while blue light has a lower speed and bends more.
A convex lens of focal length 10 cm is placed at a distance of 60 cm from a screen. How far from the lens should an object be placed so as to obtain a real image on the screen?
Given, focal length, f = 10 cm
Image distance, v = 60 cm
Object distance, u = ?
Lens formula: \frac{1}{v}-\frac{1}{u}=\frac{1}{f}
Substituting the values:
\frac{1}{60}-\frac{1}{u}=\frac{1}{10}
-\frac{1}{u}=\frac{1}{10}-\frac{1}{60}=\frac{5}{60}=\frac{1}{12}
u=-12\,\text{cm}
Therefore, the object should be placed 12 cm in front of the lens.
(a) A coin kept inside water [μ = 4/3] when viewed from air in a vertical direction appears to be raised by 3.0 mm. Find the depth of the coin in water.
(b) How is the critical angle related to the refractive index of a medium?
(a) Let the real depth of the coin be x.
μ = \frac{\text{Real depth}}{\text{Apparent depth}}=\frac{4}{3}
Therefore, apparent depth = \frac{3x}{4}.
\text{Shift}=x-\frac{3x}{4}=\frac{x}{4}
or, \frac{x}{4}=3\,\text{mm}
x = 12 mm
Hence, the depth of the coin in water is 12 mm.
(b) C=\sin^{-1}\left(\frac{1}{\mu}\right)
(a) Infrared radiations are used in warfare. Explain with reason, why.
(b) A ray of light is incident at 45° on an equilateral prism in the diagram below.
(1) Name the phenomenon exhibited by the ray of light when it enters and emerges out of the prism.
(2) State the cause of the above phenomenon mentioned by you.
(a) Infrared radiations are used for signals during warfare because they are invisible and are not absorbed much by the medium.
(b) (1) Dispersion.
(2) The speed of light in glass changes with wavelength. Different colours have different wavelengths and therefore travel at different speeds in glass, causing dispersion.
A block and tackle system of pulleys has velocity ratio 4.
(a) Draw a labelled diagram of the system indicating clearly, the direction of the load and the effort.
(b) What is the value of the mechanical advantage of the given pulley system if it is an ideal pulley system?
(a) The labelled diagram of the block and tackle system is shown below.
(b) The load is supported by four segments of the string.
L = 4T and E = T
\mathrm{M.A.}=\frac{L}{E} = 4
A metre scale of weight 50 gf can be balanced at 40 cm mark without any weight suspended on it.
(a) If this ruler is cut at its centre then state which part [0 to 50 cm or 50 to 100 cm] of the ruler will weigh more than 25 gf.
(b) What minimum weight placed on this metre ruler can balance this ruler when it is pivoted at its centre?
(a) Let the weights of the portions on the two sides of the 40 cm mark be W1 and W2.
W1 + W2 = 50 gf
Taking moments about the 40 cm mark:
40W1 = 60W2
40(50 − W2) = 60W2
W2 = 20 gf and W1 = 30 gf
Therefore, the 0 to 50 cm part of the ruler will weigh more than 25 gf.
(b) The weight of the scale acts at the 40 cm mark. For the minimum weight m placed at the 100 cm mark:
50(50 − 40) = m(100 − 50)
m = 10 gf
A car of mass 120 kg is moving at a speed 18 km/h and it accelerates to attain a speed of 54 km/h in 5 seconds. Calculate:
(a) the work done by the engine.
(b) the power of the engine.
Initial Velocity (u) = 18 km/h = 5 m/s
Final velocity (v) = 54 km/h = 15 m/s
(a) Work done = Change in kinetic energy
W= \frac{1}{2}m(v2-u2)
W= \frac{1}{2}m(152-52) = 12000 J
(b) P= \frac{W}{t}=\frac{12000}{5} = 2400 W
(a) Which characteristic of sound is affected due to the larger surface of a school bell?
(b) Calculate the distance covered by the Ultrasonic wave having a velocity of 1.5 km s⁻¹ in 14 s, when it is received after reflection by the receiver of the SONAR.
(a) Loudness.
(b) Distance = \frac{\text{Velocity}\times\text{Time}}{2}
Therefore, Distance = \frac{1.5\times14}{2} = 10.5 km
(a) Complete the following nuclear changes:
{}^{238}_{92}P\longrightarrow Q+{}^{4}_{2}He\longrightarrow R+{}^{0}_{-1}e
(b) Name the nuclear radiation which has the highest ionizing power.
(a) {}^{238}_{92}P\longrightarrow{}^{234}_{90}Q+{}^{4}_{2}He\longrightarrow{}^{234}_{91}R+{}^{0}_{-1}e
(b) Alpha (α) radiations.
We are able to see the T.V. channels clearly when we set T.V. on auto-tuning.
(a) Which phenomenon led to the clear visibility of the channels, due to auto tuning?
(b) Define the above phenomenon mentioned by you.
(c) Give any one more example of this phenomenon.
(a) Resonance.
(b) When the frequency of an externally applied periodic force is equal to the natural frequency of a body, the body begins to vibrate with an increased amplitude. This phenomenon is called resonance.
(c) The air in the sound box vibrates with a higher amplitude due to the vibrating string of a musical instrument.
(a) Define specific resistance.
(b) What happens to the specific resistance of a conductor if its length is doubled?
(c) Name a substance whose specific resistance remains almost unchanged with the increase in its temperature.
(a) Specific resistance is the resistance of a wire of that material having unit length and unit area of cross-section.
(b) It remains unchanged because specific resistance is independent of the dimensions of the conductor.
(c) Manganin.
(a) Which nuclear radiation will travel undeviated in an electric field?
(b) How can one stop the radiations escaping from a nuclear reactor in a nuclear power plant?
(c) Name one internal source of background radiations.
(a) Gamma radiation (γ).
(b) The nuclear reactor is surrounded by thick walls of lead and steel to prevent radiations from escaping.
(c) Potassium-40 present inside the human body.
Find the value of current I drawn from the cell.
(a) Calculate the current I.
(b) Calculate the terminal voltage.
(a) The two 15 Ω resistors are in series.
R1 = 15 + 15 = 30 Ω
This 30 Ω combination is in parallel with the 30 Ω resistor.
R = \frac{30\times30}{30+30} = 15 Ω
Including the internal resistance:
Rtotal = 15 + 2 = 17 Ω
I = \frac{3.4}{17} = 0.2 A
(b) V = E − Ir = 3.4 − (0.2 × 2) = 3.0 V
Calculate the total amount of heat energy required to melt 200 g of ice at 0°C to water at 100°C.
(Specific latent heat of ice = 336 J g−1, specific heat capacity of water = 4.2 J g−1 °C−1)
Mass (m) = 200 g
Specific heat capacity of water (c) = 4.2 J g-1 K-1
Specific latent heat of ice (L) = 336 J g-1
Total amount of heat energy required = ?
Heat energy taken by ice at 0° C to convert into water at 0° C
= m x L
= 200 × 336
= 67200 J
Heat energy taken by water to raise the temperature from 0° C to 100° C
= m x c x change in temperature
= 200 × 4.2 × (100 – 0)
= 200 × 4.2 × 100
= 84000 J
Total heat energy gained is
= 67200 + 84000
= 1,51,200 J
Hence, total amount of heat energy required = 1,51,200 J
(a) State the principle of calorimetry.
(b) Name the material used for making a calorimeter.
(c) Write one characteristic property of the material chosen for making a calorimeter.
(a) The principle of calorimetry states that when a hot body and a cold body are brought into contact, the heat lost by the hot body is equal to the heat gained by the cold body, provided no heat is lost to the surroundings.
(b) Thin sheets of copper.
(c) Copper has a very low specific heat capacity.
The diagram below shows a cardboard on which iron filings are kept. A wire bent in the form of a loop is seen passing through the cardboard. When current flows through it the iron filings arrange themselves as shown below.
(a) State the polarities of the battery at A and B.
(b) State the effect on the magnetic field if an iron rod is held along the axis of the coil.
(c) State one way to:
(1) Change the polarity of the coil.
(2) Decrease the strength of the magnetic field around the coil.
(a) A is positive and B is negative.
Explanation:
At the left end the magnetic field lines are anticlockwise, so by the right-hand thumb rule current emerges at A. At the right end the field lines are clockwise, so B is negative.
(b) The strength of the magnetic field increases when an iron rod is held along the axis of the coil.
(c) (1) Reverse the direction of current through the coil.
(2) Decrease the current flowing through the coil.
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