Nuclei — Physics STD 12 Science — Question

In a series LCR circuit, the voltage across the resistance, capacitance and inductance is 10 V each. If the capacitance is short circuited the voltage across the inductance will be

The energy contained in a small volume through which an electromagnetic wave is passing oscillates with:

1. Zero frequency.
2. The frequency of the wave.
3. Half the frequency of the wave.
4. Double the frequency of the wave.

If an electron revolves in the path of a circle of radius of 0.5  m at frequency of 5 × 10¹⁵ cycles/s the electric current in the circle is (Charge of an electron = 1.6 × 10^–19 C )

(a) 0.4 mA

(b) 0.8 mA

(c) 1.2 mA

(d) 1.6 mA

absorbs an energetic neutron and emits beta particles. The resulting nucleus is

(a)

(b)

(c)

(d)

The energy generated in nuclear fusion is called :

A coil of wire having finite inductance and resistance has a conducting ring placed coaxially within it. The coil is connected to a battery at time t = 0, so that a time-dependent current   starts flowing through the coil. If   is the current induced in the ring. and B(t) is the magnetic field at the axis of the coil due to , then as a function of time (t > 0), the product I₂ (t) B(t)

(a) Increases with time	(b) Decreases with time
(c) Does not vary with time	(d) Passes through a maximum

A proton is accelerated through 50,000 V. will increase Its energy by

(a) 5000 eV

(b) 8 J

(c) 5000 J

(d) 50,000 J

What is the unit of surface charge density in the SI unit?

The device, which can be used to detect whether an object is charged, is: