Total flux through a closed surface depends on:

• A) Medium only
• B) Charge and – N
• C) Charge enclosed
• D) Shape of surface

Energy density in case of a capacitor is always proportional to:

• A) E 2
• B) CV
• C) C 2
• D) V 2

Potentiometer can be used as

• A) Galvanometer
• B) Potential divider
• C) Ohm meter
• D) Ammeter

Two parallel straight wires carrying current in same direction will:

• A) Repel each other
• B) No effect
• C) Attract each other
• D) May repel or attract

If the velocity of a charged particle in perpendicular electric and magnetic field is 7.27 x 106 m/s and the Electric field is 6 x 106 N/c, what should be the value of the magnetic field?

• A) 0.45 T
• B) 0.94 T
• C) 0.78 T
• D) 0.83 T

When a dielectric material is introduced between the plates of a capacitor, what does effect it have on the capacitance?

• A) Remains the same
• B) Depends on the dielectric constant
• C) Decreases
• D) Increases

The ability of a capacitor to store charge depends upon

• A) area of plates
• B) all of these
• C) distance between plates
• D) type of dielectric used

If Io is the peak value of an AC supply, then its rms value is given as Irms:

• A) √2 Io
• B) Io/0.707
• C) Io/√2
• D) Io/2

When we accelerate the charge, which types of waves are produced?

• A) Electromagnetic waves
• B) Stationary waves
• C) Travelling waves
• D) Mechanical waves

A detector is used to detect the speed of a particular wave. If the frequency of an electromagnetic signal is 400 MHz, the speed detected by detector is __________.

• A) 300000 m/min
• B) 300000 mm/s
• C) 300000 m/h
• D) 300000 km/s

According to faraday's law, the e.m.f. induced in the coil with N turns and magnetic flux ‘φ’ is:

• A) ɛ = -N dφ/dt
• B) ɛ = -N2 dφ/dt
• C) ɛ = -N dt2/ d2φ
• D) ɛ = -N d2φ/dt2

Tesla is a unit of

• A) Mutual inductance
• B) Self-inductance
• C) Flux density
• D) Magnetic flux

Electric field due to infinite sheet of charge is

• A) infinite
• B) Varies linearly with distance
• C) Zero
• D) Independent of distance from sheet

Electric energy is measured:

• A) Kilowatt hour
• B) Kilowatt
• C) Horsepower
• D) Watt

Kirchhoff’s first rule is the manifestation of the law of conservation of:

• A) Charge
• B) Momentum
• C) Energy
• D) Mass

In Pakistan the electricity standards are:

• A) 20 Volts and 50 Hertz
• B) 10 Volts and 50 Hertz
• C) 230 Volts and 50 Hertz
• D) 30 Volts and 50 Hertz

Which statement about equipotential surfaces is correct?

• A) They are surfaces with constant electric field
• B) All points on them have the same electric potential
• C) They have varying electric potential
• D) They are always spherical

In a parallel circuit with resistors R1​ and R2​, if R1​ is much greater than R2​, what is the approximate total resistance (RT)?

• A) RT ≈ R1​ + R2​
• B) RT​ ≈ R1​ · R2​
• C) RT​ ≈ R2​
• D) RT​ ≈ R1​

What is the relationship between the electric field (E) and the dipole moment (p) at a point (r) on the axial line of the dipole?

• A) E = p
• B) E ∝ p/r³
• C) E = p/r
• D) E ∝ p/r²

When are eddy currents typically induced in a conductor?

• A) When there is no magnetic field
• B) When exposed to a changing magnetic field
• C) In the presence of a constant magnetic field
• D) In the presence of a strong magnetic field