In ballistic galvanometer, the frame on which the coil is wound is non-metallic to
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(a) Avoid the production of induced e.m.f. |
(b) Avoid the production of eddy currents |
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(c) Increase the production of eddy currents |
(d) Increase the production of induced e.m.f. |
(b) Avoid the production of eddy currents
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Two charged spheres separated at a distance d exert a force F on each other. If they are immersed in a liquid of dielectric constant 2, then what is the force (if all conditions are same)
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(a) |
(b) F |
(c) 2F |
(d) 4F |
If threshold wavelength for sodium is 6800Å then the work function will be
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(a) 1.8 eV |
(b) 2.5 eV |
(c) 2.1 eV |
(d) 1.4 eV |
Assertion : The colour of the green flower seen through red glass appears to be dark.
Reason : Red glass transmits only red light.
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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. |
A star producing light of wavelength 6000 Å moves away from the earth with a speed of 5 km/sec. Due to Doppler effect the shift in wavelength will be ( c = 3 
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(a) 0.1 Å |
(b) 0.05 Å |
(c) 0.2 Å |
(d) 1 Å |
Assertion : The magnetic filed at the ends of a very long current carrying solenoid is half of that at the center.
Reason : If the solenoid is sufficiently long, the field within it is uniform.
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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. |
