Electrostatics — Physics STD 12 Science — Question

In a region of constant electric field, the field lines are _______.

A current of 2 A flows in a system of conductors as shown. The potential difference (  will be

(a) +2V

(b) +1V

(c) -1V

(d) -2V

A transformer has 100 turns in the primary coil and carries 8 A current. If input power is one kilowatt, the number of turns required in the secondary coil to have 500V output will be

(a) 100

(b) 200

(c) 400

(d) 300

If a magnet is hanged with its magnetic axis then it stops in

(a) Magnetic meridian	(b) Geometric meridian
(c) Angle of dip	(d) None of these

The mutual inductance between a primary and secondary circuits is 0.5 H. The resistances of the primary and the secondary circuits are 20 ohms and 5 ohms respectively. To generate a current of 0.4 A in the secondary, current in the primary must be changed at the rate of

(a) 4.0 A/s

(b) 16.0 A/s

(c) 1.6 A/s

(d) 8.0 A/s

Consider the following two statements:

1. Linear momentum of the system remains constant.
2. Centre of mass of the system remains at rest.

1. ​​​​​​A implies B and B implies A.
2. A does not imply B and B does not imply A.
3. A implies B but B does not imply A.
4. B implies A but A does not imply B.

In the figure given the value of X  resistance will be, when the p.d. between B and D is zero

(a) 4 ohm

(b) 6 ohm

(c) 8 ohm

(d) 9 ohm

In photoelectric effect, electrons are ejected from metals,if the incident light has a certain minimum?

Cathode rays and canal rays produced in a certain discharge tube are deflected in the same direction if

(a) A magnetic field is applied normally	(b) An electric field is applied normally
(c) An electric field is applied tangentially	(d) A magnetic field is applied tangentially