A. Lagging each other
B. They are at 90? phase difference
C. They have zero phase difference
D. No phase difference
Alternating Current
A voltage V = V0 cos ωt is applied across a resistor of resistance R the average power dissipated per cycle in the resistor is given by___________?
A. V√/√2R
B. V/√2√R
C. V02/√2R
D. 2/√2√R
A 10Ω electric heater is connected to a 220V 50Hz mains supply. What is the peak value of the potential difference across the heater element ?
A. 220V
B. 220/ 2V
C. 110V
D. 220 √2V
An alternating current or voltage_____________________?
A. fluctuates off and on
B. varies in magnitude alone
C. changes its direction again and again
D. changes its magnitude harmonically and reverses its direction of flow after regularly recurring intervals
To find the r.m.s value of an alternating current mathematically we need to have ________________?
A. Mean value of I2
B. Square root of mean value of I2
C. Square root of I2
D. Square of 1/2
The phase angle between the voltage and the current in an AC circuit consisting of a resistance is______________?
A. Zero
B. 45°
C. 90°
D. 180°
A choke is used as a resistance in_________________?
A. DC circuit
B. AC circuits
C. Both AC and DC circuit
D. Full wave rectifier circuit
Waves emitted from the antenna are__________________?
A. Sound waves
B. Electromagnetic waves
C. Radio waves
D. Modulated waves
A wire of resistance R is coiled inductively so that its inductance is L. The impedance of the coil at a frequency of f is_______________?
A. (R+2πfL)
B. R+1/2πfL
C. (R2+f2L2)
D. (R2+4π2f2L2)
Ammeter connected in an AC circuit measures______________?
A. The exact value of the current
B. RMS value of the current
C. The net value of the current
D. The peak value of the current
