- A2.5 m V
- ✓2.5 V
- C2.5 m
- DZero
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Assertion : A double convex lens (m = 1.5) has focal length 10 cm. When the lens is immersed in water (m = 4/3) its focal length becomes 40 cm.
Reason :
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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. |
In the Bohr model of a hydrogen atom, the centripetal force is furnished by the coulomb attraction between the proton and the electron. If
is the radius of the ground state orbit, m is the mass, e is the charge on the electron and
is the vacuum permittivity, the speed of the electron is
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(a) 0 |
(b) |
(c) |
(d) |
A 20F capacitor is charged to 5V and isolated. It is then connected in parallel with an uncharged 30F capacitor. The decrease in the energy of the system will be
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(a) 25 J |
(b) 200 J |
(c) 125 J |
(d) 150 J |