1 |
Two electric bulbs of 200 W and 100 W have same voltage.If R1 and R2 be their resistance respectively then |
R<sub>1</sub> = 2R<sub>2</sub>
<span style="font-size: 14.44444465637207px;">R</span><sub>2</sub><span style="font-size: 14.44444465637207px;"> = 2R</span><sub>1</sub>
<span style="font-size: 14.44444465637207px;">R</span><sub>2</sub><span style="font-size: 14.44444465637207px;"> = 4R</span><sub>1</sub>
<span style="font-size: 14.44444465637207px;">R</span><sub>1</sub><span style="font-size: 14.44444465637207px;"> = 4R</span><sub>2</sub>
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2 |
A ten-ohm electric heater operates on a 110 V line Calculate the rate at which it develops heat in watts: |
1310 W
670 W
810 W
1210 W
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3 |
The excess (equal in number) of electrons that must be placed on each of two small spheres spaced 3 cm apart. with force of repulsion between the spheres to be 10-19 N is |
25
225
625
1250
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4 |
Two points charges A and B separated by a distance R attract each other with a force of 12 x 10-3 N. The force between A and B when the charges on them are doubled and distance is halved |
1.92 N
19.2 N
12 N
0.192 N
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5 |
A charge Q is divided into two parts q and Q - q and separated by a distance R. the force of repulsion between them will be maximum when: |
q = Q/4
q = Q/2
q = Q
None of these
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6 |
When a Na ion and a CI ion are placed in air a force F acts between them when they are separated by a distance of 1 cm from each other the permittivity of air and the dielectric constant of water are ε0 and K respectively When a piece of salt is placed in water then the force between Na+ and CI- ions separated by a distance of 1 cm will be |
F
FK/ε<sub>0</sub>
F/Kε<sub>0</sub>
F/K
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7 |
Two point charges placed at distance of 20 cm in air repel each other with a certain force.When a dielectric slab of thickness 8 cm and dielectric constant K is introduced between these point charges force of interaction becomes half of its previous value Then K is approximately. |
2
4
√2
1
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8 |
A point charge Q is placed at the mid-point of a line joining two charges 4q and q. if the net force on charge q is zero. then Q must be equal to |
-q
+q
-2q
+4q
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9 |
In a Millikan's oil drop experiment the charge on an oil drop is calculated to be 6.35 x 10-19 C. The number of excess electrons on the drop is |
3.9
4
4.2
6
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10 |
Two point charge +3μC and +8μC repel each other with a force of 40 N. if a charge of -5μC is added to each of them then the force between will become |
-10N
+10N
+20N
-20N
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11 |
What is the average energy of N molecules of monoatomic gas? |
1/2 NkT
NkT
3/2 NkT
5/2 NkT
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12 |
What is the ratio of r.m.s velocity for O2 to H2? |
1/4
4
√4 : 1
1 : √4
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13 |
At 0° K which of the following properties of a gas will be zero? |
Kinetic energy
Potential energy
Vibrational enegy
Density
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14 |
The product of the pressure and volume of an ideal gas is |
A constant
Approximately equal to the universal gas constant
Directly Proportional to its temperature
Inversely proportional to its temperature
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15 |
Boyle's law is applicable in |
Isochoric process
Isothermal process
Isobaric process
Isotonic process
|