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General
Easy
Question
If the surface temperature of the sun and its mass were to remain constant and its radius were to increase by a factor of 2, the equilibrium temperature of a planet (Tp) would
- decreases by a factor of 2
- increases by a factor of
- increase by a factor of 23/2
- increase by a factor of 4
The correct answer is: increase by a factor of 4
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Five rods of same material and same length are joined as shown. Cross-section of rods ab, ad and bc are A, 2A and 3A respectively. Ends a and c are maintained at temperatures 200°C and 0°C respectively.
If x has the value calculated in above question. Then temperature of junction b or d is:
Five rods of same material and same length are joined as shown. Cross-section of rods ab, ad and bc are A, 2A and 3A respectively. Ends a and c are maintained at temperatures 200°C and 0°C respectively.
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A wire having cross-sectional area S is attached to wall on one side and a block of mass M on the other side which placed on a horizontal surface having coefficient of friction mas shown. Material of wire has coefficient of thermal expansion and Young's modulus Y. At initial temperature there is no stress in the wire. Now the wire is cooled. At what decrease in temperature the block will begin to move.
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In figure shown on the right, the mass of the trolley is 100 kg, and it can move without friction on the horizontal floor. Its length is 12m. The mass of the girl is 50 kg. Friction exists between the shoes of the girl and the trolley’s upper surface, with 
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In figure shown on the right, the mass of the trolley is 100 kg, and it can move without friction on the horizontal floor. Its length is 12m. The mass of the girl is 50 kg. Friction exists between the shoes of the girl and the trolley’s upper surface, with = 1/3. The girl can run with a maximum speed = 9 m/s on the surface of the trolley, with respect to the surface. At t = 0 the girl starts running from rest to the right. The trolley was initially stationary.(g = 10 m/s2 )
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In figure shown on the right, the mass of the trolley is 100 kg, and it can move without friction on the horizontal floor. Its length is 12m. The mass of the girl is 50 kg. Friction exists between the shoes of the girl and the trolley’s upper surface, with = 1/3. The girl can run with a maximum speed = 9 m/s on the surface of the trolley, with respect to the surface. At t = 0 the girl starts running from rest to the right. The trolley was initially stationary.(g = 10 m/s2 )
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In figure shown on the right, the mass of the trolley is 100 kg, and it can move without friction on the horizontal floor. Its length is 12m. The mass of the girl is 50 kg. Friction exists between the shoes of the girl and the trolley’s upper surface, with = 1/3. The girl can run with a maximum speed = 9 m/s on the surface of the trolley, with respect to the surface. At t = 0 the girl starts running from rest to the right. The trolley was initially stationary.(g = 10 m/s2 )
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In figure shown on the right, the mass of the trolley is 100 kg, and it can move without friction on the horizontal floor. Its length is 12m. The mass of the girl is 50 kg. Friction exists between the shoes of the girl and the trolley’s upper surface, with = 1/3. The girl can run with a maximum speed = 9 m/s on the surface of the trolley, with respect to the surface. At t = 0 the girl starts running from rest to the right. The trolley was initially stationary.(g = 10 m/s2 )
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In figure shown on the right, the mass of the trolley is 100 kg, and it can move without friction on the horizontal floor. Its length is 12m. The mass of the girl is 50 kg. Friction exists between the shoes of the girl and the trolley’s upper surface, with = 1/3. The girl can run with a maximum speed = 9 m/s on the surface of the trolley, with respect to the surface. At t = 0 the girl starts running from rest to the right. The trolley was initially stationary.(g = 10 m/s2 )
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A 1kg block is being pushed against a wall by a force F = 75 N as shown in the Figure. The coefficient of friction is 0.25. The magnitude of acceleration of the block is
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I An initially stationary wooden block with a mass of 2 kg is pulled horizontally along a table with a time dependent force The coefficients of static and kinetic friction between the block and the table are 0.5 and 0.25 respectively. F(t) as a function of time is shown. Taking : g = 10 m/s2
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An initially stationary wooden block with a mass of 2 kg is pulled horizontally along a table with a time dependent force The coefficients of static and kinetic friction between the block and the table are 0.5 and 0.25 respectively. F(t) as a function of time is shown. Taking : g = 10 m/s2
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An initially stationary wooden block with a mass of 2 kg is pulled horizontally along a table with a time dependent force The coefficients of static and kinetic friction between the block and the table are 0.5 and 0.25 respectively. F(t) as a function of time is shown. Taking : g = 10 m/s2
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