- AElastomers
- BConductors
- CInsulators
- DPolymers
Explanation:
When an electric field is applied across the ends of conductors, the electrons begin to move under the action of the electric field. The flow of electrons constitutes electric current through the conductor.
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
A magnifying glass is used to read the newspaper. As it is moved far away from the newspaper:
The incident photon involved in the photoelectric effect experiment.
|
(a) Completely disappears |
|
(b) Comes out with an increased frequency |
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(c) Comes out with a decreased frequency |
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(d) Comes out without change in frequency |
A primary cell has an e.m.f. of 1.5 volts, when short-circuited it gives a current of 3 amperes. The internal resistance of the cell is
|
(a) 4.5 ohm |
(b) 2 ohm |
(c) 0.5 ohm |
(d) 1/4.5 ohm |
The magnetic flux linked with a coil at any instant ‘t’ is given by f = 5t3 – 100t + 300, the e.m.f. induced in the coil at t = 2 second is
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(a) – 40 V |
(b) 40 V |
(c) 140 V |
(d) 300 V |
A double convex lens of glass of m = 1.5 has radius of curvature of each of its surface is 0.2 m. The power of the lens is
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(a) + 10 dioptres |
(b) – 10 dioptres |
(c) – 5 dioptres |
(d) +5 dioptres |
Assertion : Inductance coil are made of copper.
Reason : Induced current is more in wire having less resistance.
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(a) If both assertion and reason are true and the reason is the correct explanation of the assertion. |
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(b) If both assertion and reason are true but reason is not the correct explanation of the assertion. |
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(c) If assertion is true but reason is false. |
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(d) If the assertion and reason both are false. |
An electron initially at rest, is accelerated through a potential difference of 200 volt, so that it acquires a velocity 8.4
. The value of e/m of electron will be
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(a) 2.76 |
(b) 1.76 |
(c) 0.76 |
(d) None of these |