Advertisements
Advertisements
प्रश्न
When a voltage measuring device is connected to AC mains, the meter shows the steady input voltage of 220V. This means ______.
विकल्प
input voltage cannot be AC voltage, but a DC voltage.
maximum input voltage is 220 V.
the meter reads not v but <v2> and is calibrated to read `sqrt(< v^2 >)`.
the pointer of the meter is stuck by some mechanical defect.
उत्तर
When a voltage measuring device is connected to AC mains, the meter shows the steady input voltage of 220V. This means the meter reads not v but <v2> and is calibrated to read `underline(sqrt(< v^2 >))`.
Explanation:
The voltmeter in AC circuit reads value [< v2 >] and meter is calibrated to r.m.s. value < v2 > which is multiplied by `sqrt(2)` to get Vrms.
APPEARS IN
संबंधित प्रश्न
Find the time required for a 50 Hz alternating current to change its value from zero to the rms value.
The household supply of electricity is at 220 V (rms value) and 50 Hz. Find the peak voltage and the least possible time in which the voltage can change from the rms value to zero.
The peak power consumed by a resistive coil, when connected to an AC source, is 80 W. Find the energy consumed by the coil in 100 seconds, which is many times larger than the time period of the source.
The dielectric strength of air is 3.0 × 106 V/m. A parallel-plate air-capacitor has area 20 cm2 and plate separation 0.10 mm. Find the maximum rms voltage of an AC source that can be safely connected to this capacitor.
A resistor of resistance 100 Ω is connected to an AC source ε = (12 V) sin (250 π s−1)t. Find the energy dissipated as heat during t = 0 to t = 1.0 ms.
In a series RC circuit with an AC source, R = 300 Ω, C = 25 μF, ε0 = 50 V and ν = 50/π Hz. Find the peak current and the average power dissipated in the circuit.
A small town with a demand of 800 kW of electric power at 220 V is situated 15 km away from an electric plant generating power at 440 V. The resistance of the two wire line carrying power is 0.5 Ω per km. The town gets power from the line through a 4000-220 V step-down transformer at a sub-station in the town.
(a) Estimate the line power loss in the form of heat.
(b) How much power must the plant supply, assuming there is negligible power loss due to leakage?
(c) Characterise the step up transformer at the plant.
In a transformer Np = 500, Ns = 5000. Input voltage is 20 volt and frequency is 50 HZ. Then in the output, we have,
The output of a step-down transformer is measured to be 24 V when connected to a 12-watt light bulb. The value of the peak current is ______.
In the Figure below, the current-voltage graphs for a conductor are given at two different temperatures, T1 and T2.
- At which temperature T1 or T2 is the resistance higher?
- Which temperature (T1 or T2) is higher?
