Download App

Electric Charges and Fields — Physics STD 12 Science — Question

Gujarat BoardEnglish MediumSTD 12 SciencePhysicsElectric Charges and Fields1 Mark
MCQ
A Solid sphare of radius R has a charge Q distributed in its Volume with a charge density P = Kra Where K and a are constants and r is the distance from its centre from its centre. if the electric filed at $\text{r}=\frac{\text{R}}{2}$ is $\frac{1}{8}$ times that at r = R, the value of a is.
  • A
    3
  • B
    5
  • C
    2
  • D
    7
✓

Answer

  1. 2

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Explore more

More "M.C.Q (1 Marks)" from Electric Charges and Fields→Electric Charges and Fields — all question types→Physics STD 12 Science question papers→Gujarat Board STD 12 Science question papers→Gujarat Board question paper generator→

Similar questions

In which of the following systems will the radius of the first orbit (n = 1) be minimum?
→

A frog can be deviated in a magnetic field produced by a current in a vertical solenoid placed below the frog. This is possible because the body of the frog behaves as

(a) Paramagnetic

(b) Diamagnetic

(c) Ferromagnetic

(d) Antiferromagnetic
→

Assertion  : In high latitude one sees colourful curtains of light hanging down from high altitudes.

Reason      :  The high energy charged particles from the sun are deflected to polar regions by the magnetic field of the earth.

(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.

→
A scooter starting from rest moves with a constant acceleration for a time $\triangle\text{t}_1,$ then with a constant velocity for the next $\triangle\text{t}_2,$ and finally with a constant deceleration for the next $\triangle\text{t}_3$ to come to rest. A 500N man sitting on the scooter behind the driver manages to stay at rest with respect to the scooter without touching any other part. The force exerted by the seat on the man is:
  1. 500N throughout the journey.
  2. Less than 500N throughout the journey.
  3. More than 500N throughout the journey.
  4. > 500N for time $\triangle\text{t}_1$ and $\triangle\text{t}_3$ and 500N for $\triangle\text{t}_2.$
→
A coil of self-inductance L is connected in series with a bulb B and an AC source. Brightness of the bulb decreases when:
→

Susceptibility of ferromagnetic substance is

(a) > 1

(b) < 1

(c) 0  

(d) 1
→

The ripple factor in a half wave rectifier is

(a) 1.21

(b) 0.48

(c) 0.6

(d) None of these
→

Five resistors of given values are connected together as shown in the figure. The current in the arm BD will be

(a) Half the current in the arm ABC

(b) Zero

(c) Twice the current in the arm ABC

(d) Four times the current in the arm ABC
→

Assertion :   When two coils are wound on each other, the mutual induction between the coils is maximum.

Reason     : Mutual induction does not depend on the orientation of the coils.

(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.
→

In nuclear reactions, we have the conservation of

(a) Mass only

(b) Energy only

(c) Momentum only

(d) Mass, energy and momentum
→