- Ahigh impedance
- Blow impedance
- Czero impedance
- Dimpedance of condenser is independent of frequency
Explanation
$\text{Z}=\frac{1}{\text{WC}}$
$\text{W}\downarrow\text{Z}\uparrow$
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In the half-wave rectifier circuit shown. Which one of the following wave forms is true for , the output across C and D ?
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(a)
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(b)
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(c)
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(d)
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The ionisation energy of 10 times ionised sodium atom is
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(a) 13.6 eV |
(b) 13.6 × 11 eV |
(c) |
(d) 13.6 × (11)2 eV |
The core of a transformer is laminated so that
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(a) Ratio of voltage in the primary and secondary may be increased |
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(b) Rusting of the core may be stopped |
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(c) Energy losses due to eddy currents may be reduced |
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(d) Change in flux is increased |
If the electric flux entering and leaving an enclosed surface respectively is and
the electric charge inside the surface will be
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(a) ( |
(b) ( |
(c) ( |
(d) ( |
The photoelectric threshold wavelength for potassium (work function being 2eV ) is
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(a) 310 nm |
(b) 620 nm |
(c) 1200 nm |
(d) 2100 nm |
The thermionic emission of electron is due to
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(a) Electromagnetic field |
(b) Electrostatic field |
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(c) High temperature |
(d) Photoelectric effect |
Two batteries of e.m.f. 4V and 8 V with internal resistances 1 W and 2 W are connected in a circuit with a resistance of 9 W as shown in figure. The current and potential difference between the points P and Q are
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(a) |
(b) |
(c) |
(d) |
When a beam of light is used to determine the position of an object, the maximum accuracy is achieved if the light is
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(a) Polarised |
(b) Of longer wavelength |
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(c) Of shorter wavelength |
(d) Of high intensity |