Advertisements
Advertisements
प्रश्न
The AC voltage across a resistance can be measured using
पर्याय
a potentiometer
a hot-wire voltmeter
a moving-magnet galvanometer
Advertisements
उत्तर
a hot-wire voltmeter
Only a hot-wire voltmeter can be used to measure an AC voltage across a resistor.
APPEARS IN
संबंधित प्रश्न
Show that the current leads the voltage in phase by π/2 in an AC circuit containing an ideal capacitor ?
A current i1 = i0 sin ωt passes through a resistor of resistance R. How much thermal energy is produced in one time period? A current i2 = −i0 sin ωt passes through the resistor. How much thermal energy is produced in one time period? If i1 and i2 both pass through the resistor simultaneously, how much thermal energy is produced? Is the principle of superposition obeyed in this case?
Compare resistance and reactance.
A device Y is connected across an AC source of emf e = e0 sin ωt. The current through Y is given as i = i0 sin (ωt + π/2).
- Identify the device Y and write the expression for its reactance.
- Draw graphs showing a variation of emf and current with time over one cycle of AC for Y.
- How does the reactance of the device Y vary with the frequency of the AC? Show graphically.
- Draw the phasor diagram for device Y.
When an AC voltage of 220 V is applied to the capacitor C ______.
- the maximum voltage between plates is 220 V.
- the current is in phase with the applied voltage.
- the charge on the plates is in phase with the applied voltage.
- power delivered to the capacitor is zero.
Define Capacitive reactance.
An iron cored coil is connected in series with an electric bulb with an AC source as shown in figure. When iron piece is taken out of the coil, the brightness of the bulb will ______.
A resistor of 50 Ω, a capacitor of `(25/pi)` µF and an inductor of `(4/pi)` H are connected in series across an ac source whose voltage (in volts) is given by V = 70 sin (100 πt). Calculate:
- the net reactance of the circuit
- the impedance of the circuit
- the effective value of current in the circuit.
In an alternating current circuit consisting of elements in series, the current increases on increasing the frequency of supply. Which of the following elements are likely to constitute the circuit?
When an AC voltage of 220 V is applied to the capacitor C ______.
The resistance of a coil for d.c. is 5 Ω. In a.c., the resistance will ______.
What does \[v_m\] represent?
What does \[\omega\] represent?
What is the average power over one complete cycle for a capacitor connected to an AC source?
What is the capacitive reactance of a \[15.0\,\mu\mathrm{F}\] capacitor connected to a \[50\,\mathrm{Hz}\] source?
Between which values does a current with peak current \[1.47\,\mathrm{A}\] oscillate?
What happens to the iron when an iron rod is inserted into the interior of an inductor connected to an AC source?
