Physics

When A.C current passes through a capacitor then the current relationship will be_______________?

Options:

• A. The current lead voltage by phase angle is 90 degrees
• B. The voltage leads current by phase angle is 90 degrees
• C. The current lead voltage by phase angle is 45 degrees
• D. The voltage leads current by phase angle is 45 degrees

View Answer

A. The current lead voltage by phase angle is 90 degrees

n an LCR series circuit, if V is the effective value of the applied voltage VR is the voltage across R VL is the effective voltage across L & Vc is the effective voltage across C then_______________?

Options:

• A. V = VR+VL+VC
• B. V2 = VR2+VL2+VC2
• C. V2 = VR2+(VL-VC)2
• D. V2 = VL2+(VR-VC)2

View Answer

C. V2 = VR2+(VL-VC)2

In the capacitive circuit the current___________________?

Options:

• A. Lags behind voltage by ?/2
• B. Is in phase with voltage
• C. Opposite in phase of voltage by ?
• D. Leads forward the voltage by ?/2

View Answer

D. Leads forward the voltage by ?/2

A voltage V = V0 cos ?t is applied across a resistor of resistance R the average power dissipated per cycle in the resistor is given by___________?

Options:

• A. V?/?2R
• B. V/?2?R
• C. V02/?2R
• D. 2/?2?R

View Answer

C. V02/?2R

A 100

Options:

• A. 32?
• B. 62?
• C. 50?
• D. 100?

View Answer

A. 32?

Two identical coaxial circular loops carry equal currents in the same direction. If the loops approach each other the current in______________?

Options:

• A. Each increase
• B. Each decrease
• C. Each remains the same
• D. One increases whereas that in the other decreases

View Answer

B. Each decrease

If a glass plate is inserted in between the plate of a capacitor in series with a lighted bulb the brightness of the bulb________________?

Options:

• A. Remains same
• B. Brightness increases
• C. Brightness decreases
• D. No light

View Answer

B. Brightness increases

An inductor may store energy in ________________?

Options:

• A. Its electric field
• B. Its coils
• C. Its magnetic field
• D. Both electric and magnetic fields

View Answer

C. Its magnetic field

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_______________?

Options:

• A. (R+2?fL)
• B. R+1/2?fL
• C. (R2+f2L2)
• D. (R2+4?2f2L2)

View Answer

D. (R2+4?2f2L2)

Addition of vector obeys_____________?

Options:

• A. Commutative law
• B. Distributive law
• C. Associative law
• D. All given laws in A, B and C

View Answer

D. All given laws in A, B and C