The capacitance of parallel plates capacitors varies

• A. inversely as the square of the distance between the plates
• B. directly as the square of the distance between the plates
• C. inversely as the distance between the plates
• D. directly as the distance between the plate

A negatively charged rod is brought near the cap of a gold-leaf electroscope. The cap is earthed momentarily while the rod is near to it. The rod is then removed. Which of the following is correct?

• A. The cap will be positively charged and the negatively charged leaves will diverge
• B. The cap will be negatively charged and the positively charged leaves will diverge
• C. The cap and the leaves will be positively charged
• D. The cap and the leaves will be negatively charged.

The distance between an object and its real image in a convex lens is 40cm. If the magnification of the image is 3, calculate the focal length of the lens

• A. 6.5 cm
• B. 7.5 cm
• C. 8.5 cm
• D. 4.5 cm

The instrument used in the measurement of atmospheric pressure is?

• A. Hydrometer
• B. Ratemeter
• C. Barometer
• D. Photometer

What charge is stored in a 0.1F capacitor when a 10V supply is connected across it?

• A. 1C
• B. 5C
• C. 4C
• D. 2C

The temperature of an object is raised by 120°C. The resulting increase in its absolute temperature is

• A. 50K
• B. 120 K
• C. 200K
• D. 393K

The instrument used by designers to obtain different color pattern is called?

• A) periscop
• B) sextant
• C) episcope
• D) kaleidoscope

A narrow beam of white light can be split up into different Colours by a glass prism. The correct explanation is that

• A. white light Is an electromagnetic wave
• B. the prism has all the colours of the white light
• C. different colours of white light travel with different speeds in glass
• D. white light has undergone total Internal reflection in the prism

A concave mirror has a radius of curvature of 36cm. At what distance from the mirror should an object be placed to give a real image three times the size of the object?

• A. 12cm
• B. 24cm
• C. 48cm
• D. 108cm

In a resonance tube experiment, the effective length of the air column for the first resonance is 20cm when set into vibration by a tuning fork of frequency 480Hz. Neglecting and effect, the velocity of sound in air is

• A. 96ms^-1
• B. 255ms^-1
• C. 340ms^-1
• D. 384ms^-1