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Two thin symmetrical lens of different nature have equal radii of curvature of all faces R=20 cm . The lenses are put close together and immersed in water . The focal length of system is 24cm . The difference between refractive indies of the two lenses is ………………………..x1/9 . Refractive index of wirer is 4/3

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The potential difference across 8 ohm resistance is 48v as shown in the figure . The value of potential difference across x and y points will be ……………… volts

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Two strings x and y of a sitar produce a beat frequency of 4 Hz . When the tension of the string Y is slightly increased the beat frequency is found to be 2Hz . If the frequency of x is 300Hz , then the original frequency of Y was in Hz .

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The variation of length of two metal rods A and B with change in temperature is shpown in figure . If the coefficients of linear expansion for the metal A is = n x 〖10〗^(−6) /℃ , then the value of ‘n’ will be in nearest interwar given 〖𝛼" " 〗_𝐵= 9 x〖10〗^(−6) /℃ )

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A uniform solid cylinder of mass M and radius R is placed on a rough horizontal board of same mass , which in turn is placed on a smooth surface . The coefficient of friction between the board and the cylinder is 𝜇=0.3 . If the board starts acceleration with constant acceleration a , as shown in the figure , then the maximum value of a , so that the cylinder performs pure rolling is ……………… m/𝑠^2 , g = 10 m/𝑠^2

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An arrow sign is made by cutting and re-joining a quarter part od square plate of side L=1m As shown . The distance OC , where “c” is the centre of mass of the arrow is ………cm

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In the system shown all the surfaces are frictionless while pulley and string are massless. Mass of block A is 3m and that of block B is m . If the acceleration of block B with respect to ground after system is released from rest is ‘a’ then the value of ‘10a’ is (take g= 10 , 5√2= 7.0 )

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A students performs an experiment to determine the young’s modulus of a wire , exactly 2m long buy Searle’s method . In a particular reading ,the student measures the extension in the length of the wire to be 0.8 mm with an uncertainty of ±0.05 mm at a load of exactly 1.0 kg the student also measures the diameter of the wire to be 0.4mm with an uncertainty of ± 0.01mm. Take g = 10.0 m𝑠^(−2) . The young’s modulus obtained from the reading is A) (2.0 ±0.3) x 〖10〗^11 N𝑚^(−2) B) (2.0 ±0.2) x 〖10〗^11 N𝑚^(−2) C) (2.0 ±0.1) x 〖10〗^11 N𝑚^(−2) D) (2.0 ±0.05) x 〖10〗^11 N𝑚^(−2)

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In young’s double slit experiment , the distance between the slits varies with time as d(t) = 2𝑑_𝑜 + 𝑑_𝑜sin𝜔𝑡 where 𝑑_𝑜 and 𝜔 are positive constants . The difference between the largest and the smallest fringe width obtained over time is ( D = distance between slits and screen ≫d & λ=𝑤𝑎𝑣𝑒𝑙𝑒𝑛𝑡ℎ 𝑜𝑓 𝑙𝑖𝑔ℎ𝑡 𝑢𝑠𝑒𝑑 ) A ) 𝐷λ/(2𝑑_𝑜 ) B) 𝐷λ/(3𝑑_𝑜 ) c) 2𝐷λ/(3𝑑_𝑜 ) D) 𝐷λ/(6𝑑_𝑜 )

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A pane electromagnetic wave travelling along the positive x-direction has a wavelength of 3mm . The variation in the electric field occurs in the y – direction with an amplitude 66 V/m . The equations for the electric and magnetic fields as a function of x and t are respectively . 𝐸_𝑦 = 66 cos 𝜋 x 〖10〗^11(t - 𝑥/𝑐 ) , 𝐵_𝑧 = 1.1x 〖10〗^(−7) cos 𝜋 x 〖10〗^11(t - 𝑥/𝑐 ) 𝐸_𝑦 =11 cos 2𝜋 x 〖10〗^11(t - 𝑥/𝑐 ) , 𝐵_𝑦 = 11x 〖10〗^(−7) cos 2𝜋 x 〖10〗^11(t - 𝑥/𝑐 ) 𝐸_𝑥 = 66 cos 𝜋 x 〖10〗^11(t - 𝑥/𝑐 ) , 𝐵_𝑥 = 2.2 x 〖10〗^(−7) cos 𝜋 x 〖10〗^11(t - 𝑥/𝑐 ) 𝐸_𝑦 = 66 cos 2𝜋 x 〖10〗^11(t - 𝑥/𝑐 ) , 𝐵_𝑧 = 2.2 x 〖10〗^(−7) cos 2𝜋 x 〖10〗^11(t - 𝑥/𝑐 )

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