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

Which one of the following is the velocity of a carrier wave?

• A) 3 × 108 ms-1
• B) 3 × 109 ms-1
• C) 3 × 1010 ms-1
• D) 3 × 106 ms-1

Which of the following statements is false about the properties of electromagnetic waves?

• A) The energy of the electromagnetic wave is divided equally between electric and magnetic fields.
• B) Both electric and magnetic field vectors are parallel to each other and perpendicular to the direction of propagation of wave.
• C) Both electric and magnetic field vectors attain their maximum and minimum at the same place and at the same time.
• D) These waves do not require any material medium for propagation.

An alternating current 'I0sinωt' produces heat in a given resistance at a given time, which is nearly equal to:

• A) 0.707 / I0
• B) 1/√I0
• C) 0.707 I0
• D) √I0

In the equation J = n⋅e⋅vd​, what does n represent?

• A) Total number of charge carriers
• B) Number density of charge carriers
• C) Drift velocity
• D) Negative charge

What does effect polarization have on the dipole moment in a dielectric material?

• A) Dipole moment decreases
• B) Dipole moment remains constant
• C) Dipole moment becomes zero
• D) Dipole moment increases

What property of ions determines the extent of deflection in a magnetic field in a mass spectrometer?

• A) Ion energy
• B) Ion-mass to charge ratio (m/q)
• C) Ion size
• D) Ion charge

The wave form of alternating voltage is a:

• A) Sine wave
• B) Contingent wave
• C) Tangent wave
• D) Cosine wave

Coulomb's law is only true for point charges whose sizes are

• A) very small
• B) very large
• C) large
• D) medium

In an electrical circuit with constant resistance, if the voltage source is doubled, what happens to the power delivered to the circuit?

• A) The power is halved.
• B) The power is doubled.
• C) The power remains the same.
• D) The power is quadrupled.