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Aparna Sahu
Subject: Physics
, asked on 23/4/18
Solve this:
Q.3. If the Earth were to suddenly contract to l/nth of its present radius without any change in its mass, the duration of the new day will be nearly
(a) 24 n hr.
(b) 24 hr.
(c) 24/
n
2
mgR
(d) 24
n
2
hr.
Answer
1
Aparna Sahu
Subject: Physics
, asked on 23/4/18
Solve this:
Q.20. A current of 10 A is maintained in a conductor of cross-section 1
c
m
2
. If the nondensity of free electrons be 9
×
10
28
m
-
3
the drift velocity of free electrons is
(a) 6.94
×
10
-
6
m/s
(b) 5.94
×
10
-
2
m/s
(c) 1.94
×
10
-
3
m/s
(d) 2.94
×
10
-
4
m/s
Answer
1
Aparna Sahu
Subject: Physics
, asked on 23/4/18
Q.65. A potential difference of 5 V is applied across a conductor of length 10 cm. If drift velocity of
electrons is 2.5
×
10
-
4
m/s, then electron mobility will be
(a)
5
×
10
-
4
m
2
V
-
1
S
-
1
(b)
5
×
10
-
6
m
2
V
-
1
S
-
1
(c)
5
×
10
-
2
m
2
V
-
1
S
-
1
(d) zero
Answer
1
Aparna Sahu
Subject: Physics
, asked on 22/4/18
Solve this:
Q8. The total energy, stored in the condenser system, shown in the figure below is
(A) 2 m J (B) 4 m J
(C) 8 m J (D) 16 m J
Answer
1
Maya
Subject: Physics
, asked on 21/4/18
A body thrown vertically up to reach its maximum height in t seconds. total time from the time of projection to reach a point at half of the maximum height while returning is what
Answer
1
Megha Prasadan
Subject: Physics
, asked on 20/4/18
Please explain and solve.
Questions 42-43
The graph above shows the temperature of the water
Q42. The temperature of the room in which the tank of water was cooling must have been closest to
(A) 0°C
(B) 10°C
(C) 20°C
(D) 40°C
(E) 60°C
Q43. The tank of water loses 8 ×10
5
joules of heat energy for every degree centigrade that it cools. Approximately how many joules per hour are being lost by the tank when it is at a temperature of 34°C?
(A) 0.08 × 10
6
J
(B) 8 × 10
6
J
(C) 18 × 10
6
(D) 27 ×10
6
J
(E) The approximate loss cannot be determined without knowing the mass of the water in tank.
Answer
1
Aparna Sahu
Subject: Physics
, asked on 20/4/18
Solve 56:
56. A meter scale is standing vertically on the earth's surface on one of its ends. It now falls on earth without slipping, Find the velocity with which the free end of the scale strikes the earth (9=9.8 ms
-2
)
(a) 9.8 ms
-1
(b) 5.4 ms
-1
(c) 4.5 ms
-1
(d) 1 ms
-1
Answer
1
Aparna Sahu
Subject: Physics
, asked on 19/4/18
Solve this. 24. When the temperature difference between the hot and cold junction of a thermocouple is 100 K and emf of 1 mv is generated, the thermo emf remains constant over the whole temperature range, When the temperature of the cold junction is raised by 20K, the percentage by which the emf is charged, is
(a) - 20 %
(b) 20 %
(c) 80 %
(d) - 80 %
Answer
1
Muhammad Arafath R Z
Subject: Physics
, asked on 18/4/18
Q.13. A constant voltage is applied between two ends of a metallic wire. If the length is halved and the radius of the wire is doubled, the rate of heat developed in the wire will be :
1. Doubled
2. Unchanged
3. Halved
4. Increased 8 times
Answer
1
Ian Colaco
Subject: Physics
, asked on 17/4/18
Q. Apply kirchhoffs rule to the loops PQSP and PRQP to write the expression for the currents I1, I2,I3 in the network shown in fig
Answer
1
Ian Colaco
Subject: Physics
, asked on 17/4/18
Q. Name the circuit so formed. What is the current flowing in the arm BD of this circuit? State the two laws used to find the current in difference branches of this circuit.
Answer
1
Ian Colaco
Subject: Physics
, asked on 17/4/18
Q. In the circuit shown R ]1= 4 ohm, R2=R3=5 ohm, R4=10 ohm and ɛ= 6 V. Work out the equivalent resistance of the circuit and the current in each resistor.
Answer
1
Ian Colaco
Subject: Physics
, asked on 17/4/18
A wire of 15 ohm resistance is gradually stretched to double its original length. It is then cut into two equal parts. These parts are then connected in paralllel across a 3.0 volt battery. Find the current drawn from the battery.
Answer
1
Ian Colaco
Subject: Physics
, asked on 17/4/18
How a potentiometer is used to determine the internal resistance of a given cell. (2 marks)
Answer
1
Ian Colaco
Subject: Physics
, asked on 17/4/18
Draw a circuit diagram using a metre bridge and write the necessary mathematical relation used to determine the value of an unknown resistance. Why cannot such an arrangement be used for measuring very low resistance
Answer
1
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What are you looking for?
Q.3. If the Earth were to suddenly contract to l/nth of its present radius without any change in its mass, the duration of the new day will be nearly
(a) 24 n hr.
(b) 24 hr.
(c) 24/ mgR
(d) 24 hr.
Q.20. A current of 10 A is maintained in a conductor of cross-section 1 . If the nondensity of free electrons be 9 the drift velocity of free electrons is
(a) 6.94 m/s
(b) 5.94 m/s
(c) 1.94 m/s
(d) 2.94 m/s
electrons is 2.5 m/s, then electron mobility will be
(a)
(b)
(c)
(d) zero
Q8. The total energy, stored in the condenser system, shown in the figure below is
(A) 2 m J (B) 4 m J
(C) 8 m J (D) 16 m J
Questions 42-43
The graph above shows the temperature of the water
Q42. The temperature of the room in which the tank of water was cooling must have been closest to
(A) 0°C
(B) 10°C
(C) 20°C
(D) 40°C
(E) 60°C
Q43. The tank of water loses 8 ×105 joules of heat energy for every degree centigrade that it cools. Approximately how many joules per hour are being lost by the tank when it is at a temperature of 34°C?
(A) 0.08 × 106 J
(B) 8 × 106 J
(C) 18 × 106
(D) 27 ×106J
(E) The approximate loss cannot be determined without knowing the mass of the water in tank.
56. A meter scale is standing vertically on the earth's surface on one of its ends. It now falls on earth without slipping, Find the velocity with which the free end of the scale strikes the earth (9=9.8 ms-2)
(a) 9.8 ms-1 (b) 5.4 ms-1
(c) 4.5 ms-1 (d) 1 ms-1
(a) - 20 %
(b) 20 %
(c) 80 %
(d) - 80 %
1. Doubled
2. Unchanged
3. Halved
4. Increased 8 times