Advertisements
Advertisements
प्रश्न
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 ______.
पर्याय
`1/sqrt(2) A`
`sqrt(2) A`
2 A
`2sqrt(2) A`
Advertisements
उत्तर
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 `underline(1/sqrt(2) A)`.
Explanation:
It decreases voltage and increases current
|
VS < VP NS < NP ES < EP iS < iP RS < RP tS < tP kS < 1 |
 |
According to the problem output/secondary voltage VS = 24 V
Power associated with secondary PS = 12 W
`I_S = P_S/V_S = 12/24` = 0.5 A
Amplitude of the current in the secondary winding
`I _O = I_S sqrt(2)`
= `(0.5)(1.414) = 0.707 = 1/sqrt(2) A`
APPEARS IN
संबंधित प्रश्न
The given graph shows the variation of photo-electric current (I) versus applied voltage (V) for two difference photosensitive materials and for two different intensities of the incident radiations. Identify the pairs of curves that correspond to different materials but same intensity of incident radiation.
In a series LCR circuit connected to an ac source of variable frequency and voltage ν = vm sin ωt, draw a plot showing the variation of current (I) with angular frequency (ω) for two different values of resistance R1 and R2 (R1 > R2). Write the condition under which the phenomenon of resonance occurs. For which value of the resistance out of the two curves, a sharper resonance is produced? Define Q-factor of the circuit and give its significance.
Two alternating currents are given by `i_1 = i_0 sin wt and i_2 = i_0 sin (wt + pi/3)` Will the rms values of the currents be equal or different?
An alternating current is given by i = i1 cos ωt + i2 sin ωt. The rms current is given by
A constant current of 2.8 A exists in a resistor. The rms current is
Find the time required for a 50 Hz alternating current to change its value from zero to the rms value.
An electric bulb is designed to operate at 12 volts DC. If this bulb is connected to an AC source and gives normal brightness, what would be the peak voltage of the source?
A coil of inductance 5.0 mH and negligible resistance is connected to the oscillator of the previous problem. Find the peak currents in the circuit for ω = 100 s−1, 500 s−1, 1000 s−1.
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.
Answer the following question.
A small town with a demand of 1200 kW of electric power at 220 V is situated 20 km away from an electric plant generating power at 440 V. The resistance of the two wirelines carrying power is 0.5 Ω per km. The town gets the power from the line through a 4000-220 V step-down transformer at a sub-station in the town. Estimate the line power loss in the form of heat.
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.
If `|vec"A" xx vec"B"| = sqrt3 vec"A" . vec"B"` then the value of is `|vec"A" xx vec"B"|` is
Phase diffn between voltage and current in a capacitor in A.C Circuit is.
When a voltage measuring device is connected to AC mains, the meter shows the steady input voltage of 220V. This means ______.
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?
