Physics 1st Paper CQ-Dinajpur Board-2019

প্রশ্ন ·সময় ২ ঘণ্টা ৩৫ মিনিট

1. At room temperature in a definite place a cylinder of volume 0.6 m2 0.6 \mathrm{~m}^{2} is filled up with 800gm 800 \mathrm{gm} methane (CH4) \left(\mathrm{CH}_{4}\right) gas with pressure 202650pa 202650 \mathrm{pa} . A teacher said to his students that the dew point of this place is 11.5C 11.5^{\circ} \mathrm{C} and there is a possibility of rain if the relative humidity of that place is more than 60% 60 \% . At 11C 11^{\circ} \mathrm{C} , 12C,19C 12^{\circ} \mathrm{C}, 19^{\circ} \mathrm{C} and 20C 20^{\circ} \mathrm{C} the saturated vapour pressure are 9.84 mm(Hg),10.52 mm(Hg),16.46 mm(Hg) \mathrm{mm}(\mathrm{Hg}), 10.52 \mathrm{~mm}(\mathrm{Hg}), 16.46 \mathrm{~mm}(\mathrm{Hg}) and 17.54 mm 17.54 \mathrm{~mm} (Hg) (\mathrm{Hg}) . The molecular mass of methane is 16gm/cc 16 \mathrm{gm} / \mathrm{cc} .

Din.B-19
ব্যাখ্যা আনলক করতে চর্চা প্রিমিয়াম এ আপগ্রেড করো

2. The length of a spring increases 2 cm 2 \mathrm{~cm} due to application of 80gm 80 \mathrm{gm} mass and increases its length 8 cm 8 \mathrm{~cm} due to 600gm 600 \mathrm{gm} mass. Aroni observed 1 cm 1 \mathrm{~cm} length expansion from its equilibrium position of the above spring.

Din.B-19
ব্যাখ্যা আনলক করতে চর্চা প্রিমিয়াম এ আপগ্রেড করো

3. A uniform disc (figure-2) is made by a uniform bar (figure-1).

Din.B-19
ব্যাখ্যা আনলক করতে চর্চা প্রিমিয়াম এ আপগ্রেড করো

4. The equation of a sound wave produced by a tuning fork 'A' is y=0.7sinπ(500t1.47x) y=0.7 \sin \pi(500 t-1.47 x) . All quantities mentioned in this equation are expressed in S.I unit. Another tuning fork ' B B ' made unison with the fundamental note created by the wire of sonometer having length 0.25 m 0.25 \mathrm{~m} . The wire of the sonometer is pulled with a force 5 kg 5 \mathrm{~kg} .wt and the mass of the length 1 m 1 \mathrm{~m} wire is 3gm 3 \mathrm{gm} .

Din.B-19
ব্যাখ্যা আনলক করতে চর্চা প্রিমিয়াম এ আপগ্রেড করো

5. Three forces act on a body of mass 2 kg 2 \mathrm{~kg} at a point O O for 4 s 4 \mathrm{~s} according to the figure-1. Later only 5N 5 N and 6 N 6 \mathrm{~N} forces is acting on the same body for 4s.

Din.B-19
ব্যাখ্যা আনলক করতে চর্চা প্রিমিয়াম এ আপগ্রেড করো

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