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Naga Nandhini
Subject: Physics
, asked on 28/12/17
Q. Explain the below graph, it's related to the anomalous behaviour of water.
Why it happens?
A water molecule is made of one oxygen atom combined with two hydrogen atom.
At a normal temperature, the Water molecules are held together in a liquid State because of the intermolecular attraction of the water molecules. In a liquid state, the water molecules are
constantly whizzing around in the container and are constantly being rearranged.
Answer
1
Shreya Choudhary
Subject: Physics
, asked on 26/12/17
Solve this:
Q. A stab consists of two parallel layers of two different materials of same thickness having thermal conductivities K
1
and K
2
. the equivalent conductivity of the combination is
(i) K
1
+ K
2
(2)
k
1
+
K
2
2
(3)
2
K
1
K
2
K
1
+
K
2
(4)
K
1
+
K
2
2
K
1
K
2
Answer
1
Shreya Choudhary
Subject: Physics
, asked on 26/12/17
Solve this:
Answer
1
Shreya Choudhary
Subject: Physics
, asked on 26/12/17
Solve this:
Q.24. Surface of the lake is at 2
°
C
. The temperatures of the bottom of the lake is
(1) 2
°
C
(2) 3
°
C
(3) 4
°
C
(4) 1
°
C
Answer
1
Aishwarya
Subject: Physics
, asked on 23/12/17
what is compressive strain and thermal stress also give formula
Answer
1
Shreya Choudhary
Subject: Physics
, asked on 19/12/17
on centigrade scale the temperature of a body increases by 30 degrees the increase in temperature on fahrenheit scale is (ans 54 but i m getting 86)
Answer
1
Shreya Choudhary
Subject: Physics
, asked on 18/12/17
a cylindrical beaker made of certain metal has depth of 20 cm and a capacity of 2 litre at temperature 20 degree Celsius the beaker is filled with an oil completely and heated to a temperature 80 degree Celsius calculate the amount of the oil overflown from the beaker ( coefficient of volume expansion of the Beaker's material and of oil are 0.720 ? 10 to the power minus 4 per degree Celsius and 9?10 to the power minus 4 /degree Celsius respectively)
Answer
1
Adnan Ahmed
Subject: Physics
, asked on 9/12/17
A SOLID BALL 300cm IN DIAMETER IS SUBMERGED IN A LAKE OF SUCH DEPTH THAT PRESSURE EXERTED BY WATER IS 9.8 x 10
4
N/m
2
. FIND THE CHANGE IN VOLUME OF THE BALL AT THIS DEPTH. BULK MODULUS OF THE MATERIAL OF THE BALL IS 10
12
N/m
2
.
Answer
1
Adnan Ahmed
Subject: Physics
, asked on 9/12/17
A LONGITUDINAL STRESS OF 8 x 10
7
Nm
-2
IS APPLIED IN A WIRE, WHICH INCREASES IT'S LENGTH 10
-3
TIMES. CALCULATE YOUNGS MODULUS OF THE WIRE.
Answer
1
Palak
Subject: Physics
, asked on 5/12/17
q 17 and 18 answer with solution
Q17. A big box at 100°C is connected to ice cube through two identical metal rods as shown. Ice is meting at the rate of Q
1
gram/sec. Rods are rearranged so that they are connected in series between box and ice. The new rate of meting is Q
2
gram/sec. Then
Q
2
Q
1
=
?
(1) 4 (2) 2 (3) 1/2 (4) 1/4
Q18. Uniform slab of diamension 10 cm × 10 cm × 1 cm is kept between two heat reservoirs at temperature 10°C and 90°C. The larger surface areas touch the reserviors. The thermal conductivity of the material is 0.8 W/m°C. Find the amount of heat flowing through the slab per minute.
(1) 384 J (2) 3840 J
(2) 4380 J (4) 8430 J
Answer
1
Palak
Subject: Physics
, asked on 5/12/17
q8 answer with solution
Answer
1
Palak
Subject: Physics
, asked on 4/12/17
Q3 answer with solution
Q3. A conductor of area of cross-section 100 cm and length 1 cm has coefficient of thermal conductivity 0.76 cal s
–1
m
–1
K
–1
. If 30 .8 cal of heat flows through th conductor per second. Find the temperature difference across the conductor.
(1) 40°C (2) 20°C (3) 25°C (4) 35°C
Answer
1
Arshia Sharma
Subject: Physics
, asked on 4/12/17
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Answer
2
Arshia Sharma
Subject: Physics
, asked on 4/12/17
Q. Water is boiled in a rectangular steel tank of thickness 2 cm by a constant temperature furnace . Due to vaporisation, water level falls at a steady rate of 1 cm in 9 minutes. Calculate the temperature of the furnace . Given K for steel = 0.2 cal s
-1
m
-1
°
C
-1
.
Answer
1
Arshia Sharma
Subject: Physics
, asked on 4/12/17
Solve this:
Q .Example 27.
An electric heater is used in a room of total wall area 137 m
2
to maintain a temperature of +20°C inside it, when the outside temperature is -10°C. The walls have three different layers materials. The innermost layer is of wood of thickness2.5 cm, the middle layer is of cement of thickness 1.0 cm and the outermost layer is of brick of thickness 25.0 cm. Find the power of the electric heater. Assume that there is no heat loss through th floor and the ceiling. The thermal conductivities of wood, cement and brick are 0.125,1.5 and 1.0 watt/ °C respectively.
Answer
1
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What are you looking for?
Why it happens?
A water molecule is made of one oxygen atom combined with two hydrogen atom.
At a normal temperature, the Water molecules are held together in a liquid State because of the intermolecular attraction of the water molecules. In a liquid state, the water molecules are
constantly whizzing around in the container and are constantly being rearranged.
Q. A stab consists of two parallel layers of two different materials of same thickness having thermal conductivities K1 and K2. the equivalent conductivity of the combination is
(i) K1 + K2 (2)
(3) (4)
Q.24. Surface of the lake is at 2. The temperatures of the bottom of the lake is
(1) 2
(2) 3
(3) 4
(4) 1
Q17. A big box at 100°C is connected to ice cube through two identical metal rods as shown. Ice is meting at the rate of Q1 gram/sec. Rods are rearranged so that they are connected in series between box and ice. The new rate of meting is Q2 gram/sec. Then
(1) 4 (2) 2 (3) 1/2 (4) 1/4
Q18. Uniform slab of diamension 10 cm × 10 cm × 1 cm is kept between two heat reservoirs at temperature 10°C and 90°C. The larger surface areas touch the reserviors. The thermal conductivity of the material is 0.8 W/m°C. Find the amount of heat flowing through the slab per minute.
(1) 384 J (2) 3840 J
(2) 4380 J (4) 8430 J
q8 answer with solution
Q3. A conductor of area of cross-section 100 cm and length 1 cm has coefficient of thermal conductivity 0.76 cal s–1 m–1 K–1 . If 30 .8 cal of heat flows through th conductor per second. Find the temperature difference across the conductor.
(1) 40°C (2) 20°C (3) 25°C (4) 35°C
Q .Example 27. An electric heater is used in a room of total wall area 137 m2 to maintain a temperature of +20°C inside it, when the outside temperature is -10°C. The walls have three different layers materials. The innermost layer is of wood of thickness2.5 cm, the middle layer is of cement of thickness 1.0 cm and the outermost layer is of brick of thickness 25.0 cm. Find the power of the electric heater. Assume that there is no heat loss through th floor and the ceiling. The thermal conductivities of wood, cement and brick are 0.125,1.5 and 1.0 watt/ °C respectively.