Alternating Current — Physics STD 12 Science — Question

Dual nature of radiation is shown by

(a) Diffraction and reflection	(b) Refraction and diffraction
(c) Photoelectric effect alone	(d) Photoelectric effect and diffraction

Five equal resistances each of value R are connected in a form shown alongside. The equivalent resistance of the network

(a) Between the points B and D is R	(b) Between the points B and D is
(c) Between the points A and C is R	(d) b, c

For a series LCR circuit the power loss at resonance is : -

A one metre long wire is lying at right angles to the magnetic field. A force of 1 kg wt. is acting on it in a magnetic field of 0.98 Tesla. The current flowing in it will be

(a) 100 A

(b) 10 A

(c) 1 A

(d) Zero

A thin, metallic spherical shell contains a charge Q on it. A point charge q is placed at the centre of the shell and another charge q₁ is placed outside it as shown in figure. All the three charges are positive. The force on the charge at the centre is:

Assertion  :   Leclanche cell is used, when constant supply of electric current is not required.  

Reason     : The e.m.f. of a Leclanche cell falls, if it is used continuously.

(a) If both assertion and reason are true and the reason is the correct explanation of the assertion.

(b) If both assertion and reason are true but reason is not the correct explanation of the assertion.

(c) If assertion is true but reason is false.

(d) If the assertion and reason both are false.

The difference between the mass of a nucleus and the total mass of the constituents is its.

The energy gap in case of which of the following is less than 3eV?

A particle is acted upon by a force of constant magnitude which is always perpendicular to the velocity of the particle. The motion of the particle takes place in a plane. It follows that:

1. Its velocity is constant.
2. Its acceleration is constant.
3. Its kinetic energy is constant.
4. It moves in a circular path.