1
KCET 2018
MCQ (Single Correct Answer)
+1
-0
An electron is moving in a circle of radius $r$ in a uniform magnetic field $B$. Suddenly, the field is reduced to $\frac{B}{2}$. The radius of the circular path now becomes
A
$\frac{r}{2}$
B
$2 r$
C
$\frac{r}{4}$
D
$4 r$
2
KCET 2018
MCQ (Single Correct Answer)
+1
-0
A charge $q$ is accelerated through a potential difference $V$. It is then passed normally through a uniform magnetic field, where it moves in a circle of radius $r$. The potential difference required to move it in a circle of radius $2 r$ is
A
$2 V$
B
4 V
C
1 V
D
$3 V$
3
KCET 2018
MCQ (Single Correct Answer)
+1
-0
A cyclotron's oscillator frequency is 10 MHz and the operating magnetic field is 0.66 T . If the radius of its dees is 60 cm , then the kinetic energy of the proton beam produced by the accelerator is
A
9 MeV
B
10 MeV
C
7 MeV
D
11 MeV
4
KCET 2018
MCQ (Single Correct Answer)
+1
-0
Needles $N_1, N_2$ and $N_3$ are made of a ferromagnetic, a paramagnetic and adiamagnetic substance, respectively. A magnet when brought close to them will
A
attract all three of them
B
attract $N_1$ strongly, $N_2$ weakly and repel $N_3$ weakly
C
attract $N_1$ strongly but repel $N_2$ and $N_3$ weakly
D
attract $N_1$ and $N_2$ strongly but repel $N_3$
EXAM MAP
Medical
NEETAIIMS
Graduate Aptitude Test in Engineering
GATE CSEGATE ECEGATE EEGATE MEGATE CEGATE PIGATE IN
Civil Services
UPSC Civil Service
Defence
NDA
Staff Selection Commission
SSC CGL Tier I
CBSE
Class 12