physics

The instantaneous value of the induced e.m.f as a function of time is ε = εo sin ωt where εo is the peak value of the e.m.f. The instantaneous value of the e.m.f. one quarter of the period is?

A. 0.00 B. εo/4 C. εo/2 D. εo Correct Answer: Option D = εo Explanation Period is the time to…

4 years ago

The fundamental frequency of a plucked wire under a tension of 400N is 250Hz. When the frequency is changed to 500 Hz at constant length, the tension is

A. 1600N B. 400N C. 160N D. 40N Correct Answer: Option A = 1600N

4 years ago

A blacksmith heated a metal whose cubic expansivity is 6.3 x 10^-6K−¹. The areal expansivity is?

A. 2.0 x 10-6K-1 B. 2.1 x 10-6K-1 C. 4.2 x 10-6K-1 D. 6.3 x 10-6K-1 Correct Answer: Option C…

4 years ago

A boy drags a bag of rice along a smooth horizontal floor with a force of 2N applied at the angle of 60° to the floor. The work done after a distance of 3m is?

A. 3 J B. 4 J C. 5 J D. 6 J Correct Answer: Option A - 3J Explanation Effective…

4 years ago

Silicon doped with aluminum and germanium doped with arsenic become?

A. p- and n- types respectively B. n- en p- type respectively C. p- type semiconductor D. n- type semiconductors…

4 years ago

The bond that forms a semiconductor is?

A. covalent B. electrovalent C. ionic D. metallic Correct Answer: Option A = covalent

4 years ago

The energy E of a photon and it’s wavelength is related by Eλ = X. The numerical value of X is? [h = 6.63 x 10^-34Js, C = 3 x 10^8 ms−¹]

A. 6.6 X 10-28 B. 1.99 X 10-27 C. 6.60 x 10-26 D. 1.99 x 10-25 Correct Answer: Option D…

4 years ago

A charge 50 µc has electric field strength of 360 NC‾¹ at a certain point. The electric field strength due to another charge 120 µc kept at the same distance apart and in the same medium is?

A. 864 NC‾¹ B. 150 NC‾¹ C. 144 NC‾¹ D. 18 NC‾¹ Correct Answer: Option A Explanation In general, electric…

4 years ago

The production of pure spectrum could easily be achieved using a?

A. glass prism with a pin B. triangular prism with two convex lens C. triangular prism only D. triangular prism…

4 years ago

When an object is placed between the principal focus and the optical center of a convex lens; it could be used as a?

A. Simple microscope B. refecting lens C. compound microscope D. projector Correct Answer: Option A - Simple microscope

4 years ago
Show more Posts
Show previous Posts