- Aeffective resistance due to capacity
- Beffective wattage
- Ceffective voltage
- DNone of these
Explanation:
Capacitive reactance in an A.C circuit is: $\text{X}_\text{C}=\frac{1}{\omega\text{C}}\text{ohm}$
where, C is the capacitance of capacitor and $\omega=2\pi\text{rn}$ (n is the frequency of A.C source)
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When two magnetic moments are compared using equal distance method the deflections produced are 45o and 30o. If the length of magnets are in the ratio 1 : 2, the ratio of their pole strengths is
|
(a) 3 : 1 |
(b) 3 : 2 |
(c) |
(d) 2 |
The half-life of radon is 3.8 days. Three forth of a radon sample decay in
|
(a) 5.02 days |
(b) 15.2 days |
(c) 7.6 days |
(d) 11.4 days |
The field due to a long straight wire carrying a current I is proportional to
|
(a) I |
(b) |
(c) |
(d) 1/I |
$\text{W}_2=\text{W}_1$
$\text{W}_2=\text{W}_1+\omega$
$\text{W}_2<\text{W}_1+\omega$
$\text{W}_2>\text{W}_1$
According to Joule's law, if the potential difference across a conductor having a material of specific resistance remains constant, then the heat produced in the conductor is directly proportional to
|
(a) ρ |
(b) |
(c) |
(d) |
The amplification factor of a triode is 20. If the grid potential is reduced by 0.2 volt then to keep the plate current constant its plate voltage is to be increased by
|
(a) 10 volt |
(b) 4 volt |
(c) 40 volt |
(d) 100 volt |
125 identical drops each charged to the same potential of 50 volts are combined to form a single drop. The potential of the new drop will be
|
(a) 50 V |
(b) 250 V |
(c) 500 V |
(d) 1250 V |
Which of the following radiations has the least wavelength
|
(a) X-rays |
(b) g-rays |
(c) b -rays |
(d) a-rays |