physics

A student is at a height 4m above the ground during a thunderstorm. Give that the potential difference between the thundercloud and the ground is 107v, the electric field created by the storm is?

A. 2.0 x 106 NC -1 B. 2. 5 x 106 NC -1 C. 1.0 x 107 NC -1 D. 4.0 x 107 NC -1 Correct Answer: Option…

4 years ago

A resistance R is connected across the terminal of an electric cell of internal resistance 2Ω and the voltage was reduced to 3/5 of its nominal value. The value of R is?

A. 3 Ω B. 2 Ω C. 1 Ω D. 6 Ω Correct Answer: Option A - 3 Ω Explanation…

4 years ago

A cell of internal resistance r supplies current to a 6.0Ω resistor and its efficiency is 75%. Find the value of r.

A. 4.5Ω B. 1.0Ω C. 8.0Ω D. 2.0Ω Correct Answer: Option D = 2.0Ω Explanation Efficiency = power out put/power…

4 years ago

A gas with initial volume of 2 X 10^-6 m³ is allowed to expand to six times its initial value at constant pressure of 2 x 10^5Nm−². The work done is?

A. 2.0J B. 4. 0J C. 12.0J D. 2.4J Correct Answer: Option D = 2.4J Explanation P = F/A =>…

4 years ago

A string is fastened tightly between two walls 24cm apart. The wavelength of the second overtone is?

A. 24cm B. 16cm C. 12cm D. 8cm Correct Answer: Option B - 16cm Explanation For a string fixed at…

4 years ago

A plane sound wave of frequency 85.5Hz and velocity 342ms−¹ is reflected from a vertical wall. At what distance from the wall does the wave have antinode?

A. 2m B. 4m C. 1m D. 3m Correct Answer: Option C = 1m Explanation If F = 85.5Hz, V…

4 years ago

The thermometric substance of an absolute thermometer is?

A. alcohol B. mercury C. helium D. platinum Correct Answer: Option B - mercury Explanation Mercury is the “liquid of…

4 years ago

The pressure of a given mass of a gas changes from 200Nm−² to 120Nm−² while the temperature drops from 127°C to -73°C. The ratio of the final volume to the initial volume is?

A. 2 : 5 B. 5 : 4 C. 5 : 2 D. 4 : 5 Correct Answer: Option B…

4 years ago

The driving mirror of a car has a radius of curvature of 1m. A vehicle behind the car is 4m from the mirror. Find the image distance behind the mirror?

A. 8/7 B. 4/9 C. 9/2 D. 4/7 Correct Answer: Option B - 4/9 Explanation A driving mirror is always…

4 years ago

The terrestrial telescope has one extra lens more than the astronomical telescope. The extra lens is for?

A. improving the sharpness B. creating an inverted image C. magnification of the image D. erection of the image Correct…

4 years ago
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