- AIncreases.
- BDecreases.
- CRemains same.
- DNone.
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
Assertion : When a magnetic dipole is placed in a non uniform magnetic field, only a torque acts on the dipole.
Reason : Force would also acts on dipole if magnetic field were uniform.
|
(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. |
Weber/m2 is equal to
|
(a) Volt |
(b) Henry |
(c) Tesla |
(d) All of these |
Resistance of 100 cm long potentiometer wire is 10 W, it is connected to a battery (2 volt) and a resistance R in series. A source of 10 mV gives null point at 40 cm length, then external resistance R is
|
(a) 490 W |
(b) 790 W |
(c) 590 W |
(d) 990 W |
The plates of a capacitor are charged to a potential difference of 320 volts and are then connected across a resistor. The potential difference across the capacitor decays exponentially with time. After 1 second the potential difference between the plates of the capacitor is 240 volts, then after 2 and 3 seconds the potential difference between the plates will be
|
(a) 200 and 180 V |
(b) 180 and 135 V |
(c) 160 and 80 V |
(d) 140 and 20 V |
A particle A has charge +q and a particle B has charge +4q with each of them having the same mass m. When allowed to fall from rest through the same electric potential difference, the ratio of their speed
will become
|
(a) 2 : 1 |
(b) 1 : 2 |
(c) 1 : 4 |
(d) 4 : 1 |
ABC is a right angled triangle in which AB = 3 cm and BC = 4 cm. And Ð ABC = p/2. The three charges +15, +12 and -20 e.s.u. are placed respectively on A, B and C. The force acting on B is
|
(a) 125 dynes |
(b) 35 dynes |
(c) 25 dynes |
(d) Zero |
The materials suitable for making electromagnets should have
|
(a) High retentivity and high coercivity |
(b) Low retentivity and low coercivity |
|
(c) High retentivity and low coercivity |
(d) Low retentivity and high coercivity |
In a vibration magnetometer, the time period of a bar magnet oscillating in horizontal component of earth's magnetic field is 2 sec. When a magnet is brought near and parallel to it, the time period reduces to 1 sec. The ratio H/F of the horizontal component H and the field F due to magnet will be
| (a) 3 | (b) 1/3 |
(c) |
(d) 1/ |