Advertisements
Advertisements
प्रश्न
Find the time required for a 50 Hz alternating current to change its value from zero to the rms value.
उत्तर
Data: f = 50 Hz, i = `"i"_0/sqrt2` ∴ `"i"/"i"_0 = 1/sqrt2`
i = i0 sin ωt
∴ `sin omega "t" = "i"/"i"_0 = 1/sqrt2`
∴ ωt = `pi/4` rad
∴ `2pi"ft" = pi/4`
∴ t = `1/("8f") = 1/(8(50)) = 1/400`
`= (1000 xx 10^-3)/400 = 2.5 xx 10^-3`s
APPEARS IN
संबंधित प्रश्न
Find the capacity of a capacitor which when put in series with a 10Ω resistor makes the power factor equal to 0.5. Assume an 80V-100Hz AC supply.
If the effective current in a 50 cycle AC circuit is 5 A, what is the peak value of current? What is the current 1/600 after if was zero?
What is the relation between average current and rms current over half cycle?
State the average or mean value of an alternating emf? Obtain the expression for it.
State the rms value of an alternating current? Write the relation between the rms value and peak value of an alternating current that varies with time.
Alternating current cannot be measured by D.C. ammeter because ____________.
The rms value of current in a 50 Hz AC circuit is 6 A. The average value of AC current over a cycle is ____________.
In half-wave rectifier, the RMS value of A.C. component of the wave is ____________.
Instrument which measures alternating current is based on ____________.
A 60 `Omega` electric heater is connected to a 200 V, 50 Hz mains supply. The peak value of electric current flowing in the circuit is approximately ______.
What is the r.m.s. value of an alternating current which when passed through a resistor produces heat which is four times of that produced by a direct current of 3 ampere in the same resistor?
The r.m.s. value of induced voltage in a coil of 25 turns each of area 30 sq. cm. rotating at 2000 r.p.m. about an axis at right angles to magnetic field is (B = 5 x 10-4 Wb/m2) ____________.
A player stops a football weighting 0.5 kg which comes flying towards him with a velocity of 10m/s. If the impact lasts for 1/50th sec. and the ball bounces back with a velocity of 15 m/s, then the average force involved is ______.
An alternating voltage varies with time (t) as V = 100 sin (50 πt). The rms voltage and the frequency respectively, are ______.
A 25 watt lamp is connected to a.c. potential of peak value 100 V. Calculate the rms value of the current.
An alternating voltage is given by e = 8sin628.4t. Find
- peak value of e.m.f.
- frequency or e.m.f.
- instantaneous value of e.m.f. at time t = 10. ms
