The amplification factor of a triode valve is 15. If the grid voltage is changed by 0.3 volt the change in plate voltage in order to keep the plate current constant (in volt) is
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(a) 0.02 |
(b) 0.002 |
(c) 4.5 |
(d) 5.0 |
(c) 4.5
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
Assertion : A transistor is a voltage-operating device.
Reason : Base current is greater than the collector current.
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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. |
The equivalent resistance of the arrangement of resistances shown in adjoining figure between the points A and B is
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(a) 6 ohm |
(b) 8 ohm |
(c) 16 ohm |
(d) 24 ohm |
When light falls on a metal surface, the maximum kinetic energy of the emitted photo-electrons depends upon
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(a) The time for which light falls on the metal |
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(b) Frequency of the incident light |
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(c) Intensity of the incident light |
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(d) Velocity of the incident light |
$\frac{1}{2}\text{m}\omega^2\text{A}^2$
$\frac{1}{4}\text{m}\omega^2\text{A}^2$
$\text{m}\omega^2\text{A}^2$
$\text{Zero}$
Biological importance of Ozone layer is
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(a) It stops ultraviolet rays |
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(b) Ozone rays reduce green house effect |
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(c) Ozone layer reflects radio waves |
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(d) Ozone layer controls |
The plane faces of two identical plano-convex lenses each having focal length of 40 cm are pressed against each other to form a usual convex lens. The distance from this lens, at which an object must be placed to obtain a real, inverted image with magnification one is
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(a) 80 cm |
(b) 40 cm |
(c) 20 cm |
(d) 162 cm |
A current i passes through a wire of length l, radius of cross-section r and resistivity r. The rate of heat generation is
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(a) |
(b) |
(c) |
(d) ilρ/r |
