Electrical Engineering Mcqs

When we rub a glass rod with a silk cloth then________________?

• (A)  glass rod acquires negative charge while silk acquires positive charge
• (B)  glass rod acquires positive charge while silk acquires negative charges
• (C)  both glass rod and silk acquire negative charge
• (D)  both glass rod and silk acquire positive charge

Answer

Submitted By :Ali Uppal

A coil of wire is arranged with its plane perpendicular to a uniform magnetic field o flux density B. when the radius of the coil increases from r1 to r2 in time Δt then what is the emf induced in the coil ?

• (A)  ωB/r22-r12/Δt
• (B)  ωB(r2-r1)2/Δt
• (C)  ωB(r22-r12)/Δt
• (D)  ωB(r22+r12)/Δt

Answer

Submitted By :Ali Uppal

Self-inductance of a long solenoid is______________?

• (A)  μoN2A
• (B)  μoN2/A
• (C)  μoN2
• (D)  BA

Answer

Submitted By :Ali Uppal

The alternating current has frequency of 106 Hz in such a way that time period for completion of cycle is_______________?

• (A)  1Hzs
• (B)  1.5Hzs
• (C)  106sec
• (D)  1sec

Answer

Submitted By :Ali Uppal

Self inductance of a coil depends upon________________?

• (A)  current flowing
• (B)  number of turns per unit length
• (C)  voltage produce
• (D)  all

Answer

Submitted By :Ali Uppal

Energy stored in a magnetic field is given by______________?

• (A)  LI2
• (B)  L2I/2
• (C)  LI2/2
• (D)  IL2

Answer

Submitted By :Ali Uppal

The only difference between construction of D.C generator and A.C generator is that of_______________?

• (A)  carbon brushes
• (B)  coil
• (C)  commutator
• (D)  magnetic field

Answer

Submitted By :Ali Uppal

Two oppositely charged balls A and B attract third conducting ball C when placed near them turn by turn. Then ball C must be______________?

• (A)  positively charged
• (B)  electrically neutral
• (C)  negatively charged
• (D)  positively and negatively charged

Answer

Submitted By :Ali Uppal

capacitor is to have an energy content of 20J it must be placed across a potential difference of________________?

• (A)  4 volts
• (B)  9 volts
• (C)  2 volts
• (D)  1 vol

Answer

Submitted By :Ali Uppal

A 25eV electron has a speed of______________?

• (A)  2 x 106m/sec
• (B)  3 x 106m/sec
• (C)  5 x 106m/sec
• (D)  4 x 106m/sec

Answer

Submitted By :Ali Uppal