# Tamil Nadu +2 Physics- Important One Mark Questions

Electrostatics - Set 1
1.   A glass rod rubbed with silk acquires a charge of +8×10-12. The number of electrons it has gained or lost
(a) 5×10-7    (gained)              (b) 5×107    (lost)
(c)     2×10-8    (lost)                               (d)    -8×10-1(lost)
2. Two point charges +4q and +q are placed 30cm apart.At what point on the line joining  them the electric field is zero?
(a)     15 cm from charge q            (b) 7.5 cm from charge q
(c)     20 cm from charge 4q              (d) 5 cm from charge q
3. Lines of force are the path followed by ……… in an electric field
(a)    Positive charge              (b)    negative charge
(c)    Unit positive charge                    (d)    any charge
4. The electric field intensity is 400 Vm-1 at a distance of 2 m from a point charge. It will be 100vm-1 at a distance of?
(a) 50 cm             (b) 4 cm             (c) 4 m               (d) 1.5 m
5. The unit of permittivity is
(a) C2N-1m-2        (b) Nm2C-2         (c)Hm-1     (d) NC-2m-2
6. The unit of electric flux is
a)  Nm2C-1        (b) Nm-2C-1        (c) Nm2C            (d) Nm-2C
7. An electric dipole is placed in an uniform electric field with its axis parallel to the field. It experiences
(a) only a net force         (b)neither a net force nor a torque
(c)   both a net force or torque       (d) only a torque