Solved 2022 Semester 2 Question Paper ICSE Class 10 Physics

the vibrations with a constant frequency and constant amplitude

Reason — The periodic vibrations of constant amplitude and frequency of a body in the absence of any external force on it, are called free vibrations.

Wave B

Reason — Pitch depends on frequency. Wave B has the highest frequency. So, it has the highest pitch.

A straight line passing through the origin.

Reason — The relation between potential difference (V) and current (I) is I ∝ V. So, it is an equation of a straight line passing through the origin.

a live as well as neutral wire

Reason — The main switch is connected in both the live wire and neutral wires.

the needle will deflect towards east.

Reason — As the key is closed, a current will flow through the wire and a magnetic field will be produced. In interaction with the earth’s magnetic field the resultant magnetic field will defect the needle towards east.

a current flows in the circuit.

Reason — When the current flows through the soft iron piece in the form of a closed ring, it becomes magnetised.

4 Jg^-1°C^-1

Reason — Specific heat capacity is the amount of heat energy required to raise the temperature of a substance per unit of mass. 4000 J heat is required to raise the temperature of 1 kg of water through 1°C i.e., 4000 J heat is required to raise the temperature of 1000 g of water through 1°C i.e., 4 J heat is required to raise the temperature of 1 g of water through 1°C. So, specific heat capacity of water is 4J g^-1°C^-1.

its specific heat capacity is very high so it can cool the engine without a greater increase in its own temperature.

Reason — Water in car radiators can absorb more heat without much rise in temperature due to it's high specific heat capacity. Hence, it acts as an effective coolant.

α-radiation

Reason — Alpha (α) radiation consists of alpha particles, which are composed of two protons and two neutrons. These particles are relatively large and heavy compared to other types of radiation, such as beta (β) and gamma (γ) radiation.

Carbon

Reason — The method of determining the age of archaeological material is known as Radiocarbon dating. It relies on the decay of the radioactive isotope carbon-14 to determine the age of organic materials.

(a) The switch S₁ is closed.

(b) When the key is pressed, a current passes in the wire in the direction from A to B (i.e. from south to north) and the north pole (N) of the needle deflects towards the west. There is a deflection in the magnetic compass. So, it is concluded that the switch S₁ is closed and current is flowing through the coil.

(c) The purpose of placing the magnetic compass is to determine the polarity developed at the end A of the solenoid.

(a) The reasons for using copper is that it has low specific heat capacity so the heat capacity of calorimeter is low and the amount of heat energy taken by the calorimeter from the contents to acquire it's temperature, is very small.

(b) Thermal capacity = specific heat capacity x amount of substance

∴ Thermal capacity of 40 g water = 4200 x $\dfrac{40}{1000}$ = 168 J° C^-1

(a) 12Ω and 8Ω are in parallel.

$\dfrac{1}{\text{R}}$ = $\dfrac{1}{12}$ + $\dfrac{1}{8}$ = $\dfrac{2+3}{24}$ = $\dfrac{5}{24}$

So the equivalent resistance = $\dfrac{24}{5}$ = 4.8Ω

2Ω is in series with this combination.

Hence the total resistance = 2 + 4.8 = 6.8Ω

(b) Potential difference across the 12Ω resistor = potential difference across 8Ω resistor

Or, 12 × 0.4 = 8 × I₂

∴ I₂ = $\dfrac{12 × 0.4 }{8}$ = = 0.6 A

(c) Current I = I₁ + I₂ = 0.4 + 0.6 = 1 A

(a) Brown → C

(b) Green → A

(c) Light blue → B

(a) It is generally cold after a hail storm than during and before it because after the hail storm, ice absorbs the heat energy required for it's melting from the surroundings, so the temperature of the surrounding falls further down and we feel more cold.

(b) The given statement is false. Heat energy absorbed by a body is directly proportional to the mass of the body i.e., Q ∝ m also. So, if the masses of the two bodies are different then they will absorb different amounts of heat.

Given,

Mass of metal = 420 g at temperature = 80°C

Mass of water = 80 g at temperature = 20°C

Sp. Heat of water = 4.2 J g^-1 °C^-1

Mass of calorimeter = 84 g

Sp. heat of calorimeter = 200 J kg^-1 °C^-1 = 0.2 J g^-1 °C^-1

Final temperature of mixture = 30°C

Sp. Heat of metal [S] = ?

Heat energy lost by metal
= mass of metal x specific heat capacity x fall in temperature
= 420 x S x (80-30)
= 420 x S x 50
= 21000 S J

Heat energy gained by water
= mass of water x specific heat capacity x rise in temperature
= 80 x 4.2 x (30-20)
= 80 x 4.2 x 10
= 3360 J

Heat energy gained by calorimeter
= mass of calorimeter x specific heat capacity x rise in temperature
= 84 x 0.2 x (30-20)
= 84 x 0.2 x 10
= 168 J

As, heat energy lost = heat energy gained

∴ 21000S = 3360 + 168

∴ S = $\dfrac{3528}{21000}$ = 0.168 J g^-1 °C^-1

Hence, Sp. Heat of metal = 0.168 J g^-1 °C^-1

(a) The characteristics is quality.

(b) Loudness (L) is proportional to the square of amplitude (A)

So,

$\dfrac{\text{L}_F}{\text{L}_P}$ = $\dfrac{\text{A}_F^2}{\text{A}_P^2}$

Or, $\dfrac{4}{1}$ = $\dfrac{\text{A}_F^2}{\text{A}_P^2}$

∴ $\dfrac{\text{A}_F}{\text{A}_P}$ = 2:1

(c) Pitch is that characteristic of sound by which an acute (or shrill) note can be distinguished from a grave (or flat) note of same loudness.

(a) Experimentally, it is found that the magnitude of force acting on a current carrying conductor placed in a magnetic field in the direction perpendicular to it's length, depends on the following factors —

1. The force F is directly proportional to the strength of magnetic field B, i.e., F α B
2. The force F is directly proportional to the current I flowing in the wire, i.e., F α I

(b) Fleming's left hand rule.

(a) Nuclear energy arises from radioactive processes like decay, fission, or fusion. During these changes, the combined mass of product nuclei becomes less than that of the reactant nuclei, resulting in a mass loss. This mass loss leads to liberation of energy which is known as nuclear energy.

(b) β-radiation.

(c) The nuclear reaction for β-radiation is given below:

$\begin{matrix} _{Z}^{A}\text{P} & \longrightarrow & _{Z+1}^{\space \space \space \space \space A}\text{Q} & + & \space _{-1}^{\space \space \space 0}\text{e} \\ \footnotesize{\text{Parent nucleus}} & & \footnotesize{\text{Daughter nucleus}} & & \footnotesize{\text{(Beta-particle)}} \end{matrix}$

(d) Isobars.

(a) Maximum current drawn = I = $\dfrac{\text{W}}{\text{V}}$ = $\dfrac{440}{220}$ = 2A

(b) Resistance of the appliance = R = $\dfrac{\text{W}}{\text{I}^2}$ = $\dfrac{440}{4}$ = 110Ω

(a) Frequency of E is 320 Hz.

(b) B produces large sound since the frequency of B matches with the frequency of E and resonance occurs.

(a) Melting point is 40°C and boiling point is 160°C.

(b) ²³⁵₉₂U ⟶ ²³¹₉₀Th + ⁴₂He

(a) It is damped vibration.

(b) The surrounding medium offers resistance (or friction) to the motion, so the energy of vibrating body continuously decreases due to which the amplitude of vibration gradually decreases.

(c) A body clamped at one point when disturbed slightly from its rest position, starts vibrating. The vibrations so produced are called the natural or free vibrations of the body.

(a) γ radiation.

(b) β particles.

(c) γ radiation.

(a) Given, R = 2Ω

⇒ ρ$\dfrac{\text{l}}{\text{A}}$ = 2Ω

Let new resistance be R'.

New length = $3\text{l}$

New Area = $\dfrac{\text{A}}{3}$

∴ R' = ρ$\dfrac{\text{3l}}{\dfrac{\text{A}}{3}}$

= ρ$\dfrac{\text{9l}}{\text{A}}$

= 9R = 9 × 2 = 18Ω

Hence, new resistance = 18Ω

(b) Specific resistance of the wire remains unchanged since it does not depend on the dimensions of the wire. It is the characteristic property of the substance.