Q: Question 2(iii)In the below circuit diagram, calculate:(a) the external resistance of the circuit.(b) the current I2.(c) the current I.

(a) 12Ω and 8Ω are in parallel.1R\dfrac{1}{\text{R}}R1 = 112\dfrac{1}{12}121 + 18\dfrac{1}{8}81 = 2+324\dfrac{2+3}{24}242+3 = 524\dfrac{5}{24}245So the equivalent resistance = 245\dfrac{24}{5}524 = 4.8Ω2Ω 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 resistorOr, 12 × 0.4 = 8 × I2∴ I2 = 12×0.48\dfrac{12 × 0.4 }{8}812×0.4 = = 0.6 A(c) Current I = I1 + I2 = 0.4 + 0.6 = 1 A

Q: Question 5(i)An appliance rated 440 W, 220V is connected across 220V supply.(a) Calculate the maximum current that the appliance can draw.(b) Calculate the resistance of the appliance.

(a) Maximum current drawn = I = WV\dfrac{\text{W}}{\text{V}}VW = 440220\dfrac{440}{220}220440 = 2A(b) Resistance of the appliance = R = WI2\dfrac{\text{W}}{\text{I}^2}I2W = 4404\dfrac{440}{4}4440 = 110Ω

Question 1

Question 1(iv)A main switch in the main distribution board is present in :a live wirea neutral wirea live as well as neutral wirean earth wire

Accepted Answer

a live as well as neutral wireReason — The main switch is connected in both the live wire and neutral wires.

Question 2

Question 2(i)The diagram below shows a magnetic compass kept closer to a coil AB wound around a hollow cylindrical cardboard :(a) After studying the circuit and the magnetic compass carefully, state whether the switch S1 is open or closed.(b) How did you arrive at the conclusion in (a)?(c) What is the purpose of placing the magnetic compass in the above setup?

Accepted Answer

(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.

Question 3

Question 2(ii)(a) Give an important reason for copper to be used as a material for a calorimeter.(b) Calculate the thermal capacity of 40 g of water.[Specific heat capacity of water = 4200 JKg-1°C-1]

Accepted Answer

(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 401000\dfrac{40}{1000}100040​ = 168 J° C-1

Question 4

Question 2(iii)In the below circuit diagram, calculate:(a) the external resistance of the circuit.(b) the current I2.(c) the current I.

Accepted Answer

(a) 12Ω and 8Ω are in parallel.1R\dfrac{1}{	ext{R}}R1​ = 112\dfrac{1}{12}121​ + 18\dfrac{1}{8}81​ = 2+324\dfrac{2+3}{24}242+3​ = 524\dfrac{5}{24}245​So the equivalent resistance = 245\dfrac{24}{5}524​ = 4.8Ω2Ω 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 resistorOr, 12 × 0.4 = 8 × I2∴ I2 = 12×0.48\dfrac{12 × 0.4 }{8}812×0.4​ = = 0.6 A(c) Current I = I1 + I2 = 0.4 + 0.6 = 1 A

Question 5

Question 3(ii)(a) Why does it become colder after a hailstorm than during or before the hailstorm?(b) 'If two bodies have the same specific heat capacities, then they will always absorb the same amount of heat if their temperature increases by the same amount.' State whether the given statement is true or false.

Accepted Answer

(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.

Question 6

Question 3(iii)A metal piece of mass 420 g present at 80°C is dropped in 80 g of water present at 20°C in a calorimeter of mass 84 g. If the final temperature of the mixture is 30°C, then calculate the specific heat capacity of the metal piece.[Specific heat capacity of water = 4.2 Jg-1 °C-1, Specific heat capacity of the calorimeter = 200 Jkg-1 °C-1]

Accepted Answer

Given,Mass of metal = 420 g at temperature = 80°CMass of water = 80 g at temperature = 20°CSp. Heat of water = 4.2 J g-1 °C-1Mass of calorimeter = 84 gSp. heat of calorimeter = 200 J kg-1 °C-1 = 0.2 J g-1 °C-1Final temperature of mixture = 30°CSp. 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 JHeat 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 JHeat 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 JAs, heat energy lost = heat energy gained∴ 21000S = 3360 + 168∴ S = 352821000\dfrac{3528}{21000}210003528​ = 0.168 J g-1 °C-1Hence, Sp. Heat of metal = 0.168 J g-1 °C-1

Question 7

Question 4(i)Rohit playing a flute and Anita playing a piano emit sounds of same pitch and loudness.(a) Name one characteristic that is different for waves from the two different instruments.(b) If now the loudness of the sound from flute becomes four times that of the sound from piano, then write the value of the ratio AF : AP (AF – amplitude of sound wave from flute, AP – amplitude of sound wave from piano)(c) Define 'Pitch' of a sound.

Accepted Answer

(a) The characteristics is quality.(b) Loudness (L) is proportional to the square of amplitude (A)So,LFLP\dfrac{	ext{L}_F}{	ext{L}_P}LP​LF​​ = AF2AP2\dfrac{	ext{A}_F^2}{	ext{A}_P^2}AP2​AF2​​Or, 41\dfrac{4}{1}14​ = AF2AP2\dfrac{	ext{A}_F^2}{	ext{A}_P^2}AP2​AF2​​∴ AFAP\dfrac{	ext{A}_F}{	ext{A}_P}AP​AF​​ = 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.

Question 8

Question 4(ii)(a) Name two factors on which the force experienced by a conductor carrying current, placed in a magnetic field, depends. Also, state how these factors affect the force.(b) With the help of which rule you can determine the direction of force acting on a current carrying conductor placed in a magnetic field?

Accepted Answer

(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 —The force F is directly proportional to the strength of magnetic field B, i.e., F α BThe force F is directly proportional to the current I flowing in the wire, i.e., F α I(b) Fleming's left hand rule.

Question 9

Question 4(iii)(a) What is nuclear energy?(b) After emission of a nuclear radiation, the atomic number of the daughter nucleus increases by 1. Identify the nuclear radiation.(c) Write a nuclear reaction indicating the nuclear change mentioned in (b).(d) What is the special name given to the parent and daughter nucleus when this radiation is emitted?

Accepted Answer

(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:ZAP⟶Z+1     AQ+ −1   0eParent nucleusDaughter nucleus(Beta-particle)\begin{matrix} _{Z}^{A}	ext{P} & \longrightarrow & _{Z+1}^{\space \space \space \space \space A}	ext{Q} & + & \space _{-1}^{\space \space \space 0}	ext{e} \ \footnotesize{	ext{Parent nucleus}} & & \footnotesize{	ext{Daughter nucleus}} & & \footnotesize{	ext{(Beta-particle)}} \end{matrix}ZA​PParent nucleus​⟶​Z+1     A​QDaughter nucleus​+​ −1   0​e(Beta-particle)​(d) Isobars.

Question 10

Question 5(i)An appliance rated 440 W, 220V is connected across 220V supply.(a) Calculate the maximum current that the appliance can draw.(b) Calculate the resistance of the appliance.

Accepted Answer

(a) Maximum current drawn = I = WV\dfrac{	ext{W}}{	ext{V}}VW​ = 440220\dfrac{440}{220}220440​ = 2A(b) Resistance of the appliance = R = WI2\dfrac{	ext{W}}{	ext{I}^2}I2W​ = 4404\dfrac{440}{4}4440​ = 110Ω

Question 11

Question 5(ii)The diagram below shows a vibrating tuning fork E mounted on a sound box X. When the vibrating tuning forks A, B, C and D are placed on the sound box Y one by one, it is observed that a louder sound is produced when the tuning fork B is place on Y.(a) What is the frequency of tuning fork E?(b) Why does B produce a louder sound?

Accepted Answer

(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.

Question 12

Question 5(iii)(a) From the graph of heating curve given below state the melting point and boiling point of the substance.(b) Complete and rewrite the following nuclear reaction by filling in the blanks.235U ⟶ + 90Th + 42He

Accepted Answer

(a) Melting point is 40°C and boiling point is 160°C.(b) 23592U ⟶ 23190Th + 42He

Question 13

Question 6(i)Study the below figure and answer the following :(a) What type of vibration does the figure represent?(b) State one reason for which the amplitude of the vibration decreases with time.(c) Write an example of natural vibrations.

Accepted Answer

(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.

Question 14

Question 6(ii)A certain beam of α particles, β particles and γ radiations travel through a region of electric field produced between two oppositely charged parallel plates A(+) and B(–).(a) Which of the above three has the maximum speed?(b) Which one deviates the most from its original path?(c) Which one does not deviate at all when passing through a region of electric or magnetic field?

Accepted Answer

(a) γ radiation.(b) β particles.(c) γ radiation.

Question 15

Question 6(iii)If a wire of resistance 2Ω gets stretched to thrice its original length :(a) Calculate the new resistance of the wire.(b) What happens to the specific resistance of the wire?

Accepted Answer

(a) Given, R = 2Ω⇒ ρlA\dfrac{	ext{l}}{	ext{A}}Al​ = 2ΩLet new resistance be R'.New length = 3l3	ext{l}3lNew Area = A3\dfrac{	ext{A}}{3}3A​∴ R' = ρ3lA3\dfrac{	ext{3l}}{\dfrac{	ext{A}}{3}}3A​3l​= ρ9lA\dfrac{	ext{9l}}{	ext{A}}A9l​= 9R = 9 × 2 = 18ΩHence, 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.

Solved 2022 Semester 2 Question Paper ICSE Class 10 Physics

Section A 10 Marks

Section B 30 Marks