Physics — Suggested Paper 2

1(i). When the speed of a moving object is doubled, then its kinetic energy: (a) remains the same (b) decreases (c) is doubled (d) becomes four times

1(ii). Select a correct option with respect to echo depth sounding: (a) infrasonic waves are used (b) the frequency of the waves used is between 20 Hz and 20,000 Hz. (c) ultrasonic waves are used. (d) supersonic waves are used.

1(iii). In the circuit given below, identify the lamp (L1, L2, L3 and L4) whose failure would not interrupt the power supply to the other lamps. (a) L1 (b) L2 (c) L3 (d) L4

1(iv). Specific heat capacity of a substance X is 1900 Jkg-1°C-1 means: (a) Substance X absorbs 1900 J for 1°C rise in temperature (b) 1 kg of substance X absorbs 1900 J heat for 1°C rise in temperature (c) 1 kg of substance X absorbs 1900 J heat to increase the temperature (d) 1 kg of substance X absorbs 1900 J heat to cool down by 1°C

1(v). The deviation produced by an equilateral prism does not depend on: (a) the angle of incidence. (b) the size of the prism. (c) the material of the prism. (d) the colour of light used.

1(vi). When a ray of light passes from one optical medium to another, which of the following physical quantities does NOT change? (a) Amplitude of the wave (b) Frequency of the wave (c) Wavelength of the wave (d) Speed of the wave

1(vii). The diagram below shows the balanced position of a metre scale. Which one of the following diagrams shows the correct position of the scale when it is supported at the centre?

1(viii). A single fixed pulley is used because: (a) it changes the direction of applied effort conveniently. (b) it multiplies speed. (c) it multiplies effort. (d) its efficiency is 100%.

1(ix). To study the age of excavated material of archaeological significance we study the rate of decay of an isotope of : (a) Uranium (b) Cobalt (c) Carbon (d) Chlorine

1(x). A concave lens produces only ............... image. (a) real, enlarged (b) virtual, enlarged (c) virtual, diminished (d) real, diminished

1(xi). A coil wound around a piece of soft iron can become an electromagnet only when: (a) the circuit is open. (b) a magnetic compass is present in the vicinity. (c) a galvanometer is connected to the circuit. (d) a current flows in the circuit.

1(xii). Identify the option that displays the correct wiring with correct colour code :

1(xiii). The energy change during photosynthesis in plants is: (a) heat to chemical. (b) light to chemical. (c) chemical to light. (d) chemical to heat.

1(xiv). Equal volumes of water are added to three cylindrical jars A, B and C of same height and radii rA, rB and rC respectively with rB < rA < rC. If you blow air into the mouth of these jars, which tube will produce the shrillest note? (a) A (b) B (c) C (d) All will produce the notes of same shrillness

1(xv). In the given circuits Y and Z, the resistors, R1 and R2, are connected in : (a) series in both the circuits (b) parallel in both the circuits (c) parallel in Y and series in Z (d) series in Y and parallel in Z

2(i)(a). A car is moving in uniform circular motion. The direction of friction between the tyres and the path is ............... [towards the centre / tangential to the path].

2(i)(b). When a ray of light passes from a denser to a rarer medium, its wavelength ............... [decreases / increases].

2(i)(c). The lid of a calorimeter minimises heat loss by ............... [convection / radiation].

2(i)(d). Quality of sound depends on its ............... [amplitude / waveform].

2(i)(e). A substance whose resistance becomes almost negligible at a temperature near absolute zero is called a ............... [semiconductor / superconductor].

2(i)(f). ............... radiation deviates minimum in a magnetic field [Alpha / Beta].

2(ii)(a). What is the advantage of using a block and tackle system over a single movable pulley?

2(ii)(b). Why should she connect more number of pulleys in the upper fixed block?

2(iii). State two factors upon which the rate of emission of thermions depends.

3(i)(a). Which of the two, alternating current or direct current, produces a varying magnetic field when it flows through a conductor?

3(i)(b). State the frequency of the alternating current supply in India

3(ii)(a). Which substance will have more specific heat capacity?.

3(ii)(b). Which substance will show greater rise in temperature if the same amount of heat is supplied to both?

3(iii). The V-I graph for a series combination and for a parallel combination of two resistors is shown in the figure below. Which of the two A or B, represents the parallel combination? Give a reason for your answer.

3(iv)(i). It produces a real and same size image of the object.

3(iv)(ii). It is used as a magnifying lens.

3(v)(a). Which electrical component protects the electric circuit in case of excess current and which can also be used as a switch?

3(v)(b). Name the wire to which this electrical component is connected in an electric circuit.

3(vi)(i). intensities and

3(vi)(ii). frequencies?

3(vii)(a). Which point on the graph indicates the element Cm?

3(vii)(b). Which point on the graph indicates daughter nucleus after Cm undergoes radioactive decay of 1α followed by 2β?

3(vii)(c). State the mass number of the daughter nucleus.

4(i). Akash takes a uniform metre scale and suspends a weight of 2 N at one end ‘X’, and a weight of 5 N on the other end ‘Y”. He then balances the ruler horizontally on a knife edge placed at 70 cm from X. Draw a diagram of the arrangement and calculate the weight of the ruler.

4(ii)(a). Which class of lever do these belong to?

4(ii)(b). Among these (X, Y or Z) which one will give the maximum mechanical advantage? Justify your answer.

4(iii)(a). the kinetic energy of Richa at point Q

4(iii)(b). the vertical height of point P above the ground. (use g as 10 m/s2 and neglect friction)

4(iii)(c). the kinetic energy of Richa at point R. (While moving from Q to R, she loses 500 J of energy against friction.)

5(a)(i). What is the angle through which the incident ray deviates and emerges out of the prism?

5(a)(ii). Name the instrument where this action of prism is put into use.

5(a)(iii). Which prism surface will behave as a mirror?

5(b). An object AB is placed between O and F1 on the principal axis of a 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.

5(c)(i). the position of the image

5(c)(ii). nature of the image

6(i). An object is placed in front of a concave lens at a distance of 45 cm from it. If its image is formed at a distance of 30 cm from the lens, calculate the focal length of the lens.

6(ii)(a). have greater lateral displacement on emerging out of the block?

6(ii)(b). travel with greater speed in the block?

6(ii)(c). scatter more in the atmosphere?

6(iii)(a)(1). for which a quartz prism is used to study the spectrum.

6(iii)(a)(2). which are used in remote sensing devices.

6(iii)(a)(3). which are used in traffic signals in India.

6(iii)(b). Name one property common to all electromagnetic radiations.

7(i)(a). Refractive index of glass with respect to water is 9/8. Find the refractive index of water with respect to glass.

7(i)(b). Name the principle used to find the value in part (a).

7(i)(c). If we change the temperature of water, then will the ratio 9/8 remain the same? Write Yes or No.

7(ii)(a). ‘Light covers a distance of ‘20x’ units in time ‘t1’ in diamond.’ State true or false.

7(ii)(b). Calculate the refractive index of the medium in terms of ‘t1’ and ‘t2’.

7(iii)(a). Copy the diagram and complete the path of the ray PQ.

7(iii)(b). State two factors on which the angle of deviation depends.

8(a)(i). Name the waves used for echo depth sounding.

8(a)(ii). Give one reason for their use for the above purpose.

8(a)(iii). Why are the waves mentioned by you not audible to us?

8(b)(i). What is an echo?

8(b)(ii). State two conditions for an echo to take place.

8(c)(i). Name the phenomenon involved in tuning a radio set to a particular station.

8(c)(ii). Define the phenomenon named by you in part (i) above.

8(c)(iii). What do you understand by loudness of sound?

8(c)(iv). In which units is the loudness of sound measured?

9(a)(i). A fuse is rated 8A. Can it be used with an electrical appliance rated 5 KW, 200 V? Give a reason.

9(a)(ii). Name two safety devices which are connected to the live wire of a household electric circuit.

9(b)(i). Find the equivalent resistance between A and B

9(b)(ii). State whether the resistivity of a wire changes with the change in the thickness of the wire.

9(c)(i). If the iron is used for 2h daily, find the cost of running it for one week if it costs ₹4.25 per kWh

9(c)(ii). Why is the fuse absolutely necessary in a power circuit?