Science (English Medium) कक्षा १२ - CBSE Question Bank Solutions

Each element is associated with a ______.

Continuous spectrum is produced by ______.

An electron makes a transition from orbit n = 4 to the orbit n = 2 of a hydrogen atom. What is the wave number of the emitted radiations? (R = Rydberg's constant)

Absorption line spectrum is obtained ______.

To produce an emission spectrum of hydrogen it needs to be ______.

Relation between atomic number (Z), neutron number (N) and mass number (A) is ______.

The nuclei of isotopes of a given element differ from each other in their number of ______.

Lenz’s law is a consequence of the law of conservation of ______.

In an L.C.R. series a.c. circuit, the current ______.

If an LCR series circuit is connected to an ac source, then at resonance the voltage across ______.

In series combination of R, L and C with an A.C. source at resonance, if R = 20 ohm, then impedence Z of the combination is ______.

In an LCR series a.c. circuit, the voltage across each of the components, L, C and R is 50V. The voltage across the LC combination will be ______.

Assertion: When the frequency of the AC source in an LCR circuit equals the resonant frequency, the reactance of the circuit is zero, and so there is no current through the inductor or the capacitor.
Reason: The net current in the inductor and capacitor is zero.

A coil of 40 henry inductance is connected in series with a resistance of 8 ohm and the combination is joined to the terminals of a 2 volt battery. The time constant of the circuit is ______.

Which of the following statements is not correct?

In series LCR circuit, the phase angle between supply voltage and current is ______.