A metallic sheet is inserted between the plates of a parallel plate capacitor. The capacitance of the capacitor
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(a) Increases |
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(b) Is independent of the position of the sheet |
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(c) Is maximum when the metal sheet in the middle |
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(d) a, b |
(d) a, b
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Assertion : An electric bulb is first connected to a dc source and then to a ac source having the same brightness in both the cases.
Reason : The peak value of voltage for an A.C. source is 
times the root mean square voltage.
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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 assertion is false but reason is true. |
When a ray of light passes from a denser to a rarer medium, some part of it gets ....... into the denser medium:
$\text{v}_0=0,\ \text{a}_0=0$
$\text{v}_0=0,\ \text{a}_0\neq0$
$\text{v}_0\neq0,\ \text{a}_0=0$
$\text{v}_0\neq0,\ \text{a}_0\neq0$
3 identical bulbs are connected in series and these together dissipate a power P. If now the bulbs are connected in parallel, then the power dissipated will be
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(a) |
(b) 3P |
(c) 9P |
(d) |
The resistance and inductance of series circuit are 5
and 20H respectively. At the instant of closing the switch, the current is increasing at the rate 4A - s. The supply voltage is
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(a) 20 V |
(b) 80 V |
(c) 120 V |
(d) 100 V |
A person uses spectacles of power +2D. He is suffering from
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(a) Short sightedness or myopia |
(b) Long sightedness or hypermetropia |
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(c) Presbyopia |
(d) Astigmatism |
Light from sodium lamp is passed through cold sodium vapours, the spectrum of transmitted light consists of
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(a) A line at 5890 Å |
(b) A line at 5896 Å |
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(c) Sodium doublet lines |
(d) No spectral features |
