Pakistan MCQs

Parallel resistors share the same voltage.
The total resistance is less than the smallest branch resistance.

The object is at twice the focal length.
Using the lens equation gives di=40 cm.

Electrical power can be written P=VI.
It may also be expressed as I²R or V²/R.

Magnification magnitude is image height divided by object height.
30/10 = 3.

A capacitor consists of separated conductors.
Its capacitance measures charge stored per unit potential difference.

In-phase displacements add constructively.
The resultant amplitude is 3+2 = 5 cm.

A diverging lens causes rays to separate.
Their backward extensions meet at a virtual focal point.

Opposite-phase amplitudes subtract.
The resultant amplitude is |5-3| = 2 cm.

For the fundamental, the string length is half a wavelength.
λ=2L=2.4 m.

The fundamental wavelength is 2L=1.5 m.
F=v/λ=300/1.5 = 200 Hz.

For an open pipe, fundamental wavelength is 2L=1.7 m.
F=340/1.7 = 200 Hz.

For a closed pipe, fundamental wavelength is 4L=3.4 m.
F=340/3.4 = 100 Hz.