Dual Nature of Radiation and Matter — Physics STD 12 Science — Question

In the figure shown, the effective capacitance between the points A and B, if  each has capacitance C, is

(a) 2C

(b)

(c) 5C

(d)

Two batteries, one of emf 18 volts and internal resistance 2Ω and the other of emf 12 volt and internal resistance 1 Ω, are connected as shown. The voltmeter V will record a reading of

(a) 15 volt

(b) 30 volt

(c) 14 volt

(d) 18 volt

The focal length of a normal eye-lens is about:

1. 1mm.
2. 2cm.
3. 25cm.
4. 1m.

The reason for attractive force between two parallel wires in which current is flowing in same direction is:

Excitation energy of a hydrogen like ion in its excitation state is 40.8 eV. Energy needed to remove the electron from the ion in ground state is:

Which of the following statements is wrong ? Magnetic lines of force:

A body has – 80 micro coulomb of charge. Number of additional electrons in it will be

(a) 8

(b) 80

(c) 5

(d) 1.28

The energy gap in glass at room temperature is:

Identify which of the following statement best describe a nuclear reaction.