physics

A cell of e.m.f 12V and internal resistance 4Ω is connected to an external resistor of resistance 2Ω. Find the current flow.

A. 5 A B. 4 A C. 3 A D. 2 A Correct Answer: Option D = 2 A Explanation…

5 years ago

Three capacitors of capacitance 2μF; 4μFand 8μF are connected in parallel and a P.D of 6V is maintained across each capacitor. The total energy stored is?

A. 2.52 x 10-6J B. 6.90 x 10-6J C. 2.52 x 10-4J D. 6.90 x 10-4J Correct Answer: Option C…

5 years ago

The velocity of sound in air at 16°C is 340ms‾¹. What will it be when the pressure is doubled and its temperature raised to 127°C?

A. 400 ms‾¹ B. 4,000 ms‾¹ C. 8,000 ms‾¹ D. 160,000 ms‾¹ Correct Answer: Option A - 400 ms‾¹

5 years ago

Which of the following is a pure semiconductor?

A. carbon B. silicon C. transistor D. phosphorus Correct Answer: Option B - silicon Explanation A semiconductor is a material…

5 years ago

Transistors are used for the?

A. rectification of signals B. conversion of a.c to d.c C. amplification of signals D. conversion of d.c to a.c…

5 years ago

The ground stated energy for the hydrogen atom is 5.44 x 10^-19J . If an electron drops from zero energy to ground state, calculate the frequency of the emitted radiation. [h = 6.6 x 10^-34 Js]

A. 5.0 x 1016 Hz B. 2.0 x 1016 Hz C. 5.0 x 1015 Hz D. 2.0 x 1015 Hz…

5 years ago

In a discharge tube; most of the gas is pumped out so that electricity is conducted at?

A. low voltage B. steady voltage C. high pressure D. low pressure Correct Answer: Option D - low pressure Explanation…

5 years ago

In alternating current circuit at resonance; the angel of lead or lag is?

A. π° B. (π)/2° C. (π)/3° D. 0° Correct Answer: Option D = 0°

5 years ago

Two inductors of inductances 5mll and 15mll are connected in series and a current of 5A flows through them. The total energy stored in the inductor is?

A. 500.0J B. 250.0J C. 62.5J D. 50.0J E. no correct option Correct Answer: Option E = no correct option…

5 years ago

A galvanometer with full-scale deflection of 10mA is to be converted to a voltmeter with full-scale deflection of 5V. The resistance of the galvanometer is?

A. 1Ω B. 2Ω C. 5Ω D. 10Ω Correct Answer: Option D = 10Ω Explanation R = (Vg)/lg = G,…

5 years ago
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