Questions in Alternating Current

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	The power is transmitted from a power house on high voltage ac because
	The potential difference V and the current i flowing through an instrument in an ac circuit of frequency f are given by $V = 5\cos \omega \,t$ volts and $I = 2\sin \omega t$ amperes (where $\omega = 2\pi f$). The power dissipated in the instrument is
	In an ac circuit, V and I are given by $V = 100 sin (100 t)$ volts, $I = 100\sin \,\left( {100t + \frac{\pi }{3}} \right)\,mA$. The power dissipated in circuit is
	Alternating current can not be measured by dc ammeter because
	The resistance of a coil for dc is in ohms. In ac, the resistance
	If instantaneous current is given by $i = 4\cos \,(\omega \,t + \varphi )$ amperes, then the r.m.s. value of current is
	In an ac circuit, peak value of voltage is 423 volts. Its effective voltage is
	In an ac circuit $I = 100 sin 200 \omega t$. The time required for the current to achieve its peak value will be
	The peak value of an Alternating current is 6 amp, then r.m.s. value of current will be
	A generator produces a voltage that is given by $V = 240\sin 120\,t$, where t is in seconds. The frequency and r.m.s. voltage are

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