- ✓law of conservation of energy
- Blaw of conservation of charge
- Claw of conservation of current
- Dlaw of conservation of momentum
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Assertion : Two P-N junction diodes placed back to back, will work as a NPN transistor.
Reason : The P-region of two PN junction diodes back to back will form the base of NPN transistor.
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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 example of a diamagnetic substance is
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(a) Aluminium |
(b) Copper |
(c) Iron |
(d) Nickel |
A coil of N turns and mean cross-sectional area A is rotating with uniform angular velocity w about an axis at right angle to uniform magnetic field B. The induced e.m.f. E in the coil will be
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(a) NBA sinwt |
(b) NB w sinwt |
(c) NB/A sinwt |
(d) NBA w sinwt |
In a primary coil 5A current is flowing on 220 volts. In the secondary coil 2200V voltage produces. Then ratio of number of turns in secondary coil and primary coil will be
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(a) 1 : 10 |
(b) 10 : 1 |
(c) 1 : 1 |
(d) 11 : 1 |
The velocity factor of a transmission line x. If dielectric constant of the medium is 2.6, the value of x is
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(a) 0.26 |
(b) 0.62 |
(c) 2.6 |
(d) 6.2 |
Three bulbs of 40W, 60W and 100W are arranged in series with 220V. Which bulb has minimum resistance
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(a) 40W |
(b) 60W |
(c) 100W |
(d) Equal in all bulbs |
A light of wavelength 5890 Å falls normally on a thin air film. The minimum thickness of the film such that the film appears dark in reflected light
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(a) 2.945 |
(b) 3.945 |
(c) 4.95 |
(d) 1.945 |