1
KCET 2017
MCQ (Single Correct Answer)
+1
-0
$4 \times 10^{10}$ electrons are removed from a neutral metal sphere of diameter 20 cm placed in air. The magnitude of the electric field (in $\mathrm{NC}^{-1}$ ) at a distance of 20 cm from its centre is
A
640
B
5760
C
Zero
D
1440
2
KCET 2017
MCQ (Single Correct Answer)
+1
-0
The mass defect of ${ }_2^4 \mathrm{He}$ is 0.03 u . The binding energy per nucleon of helium (in MeV) is
A
6.9825
B
27.93
C
2.793
D
69.825
3
KCET 2017
MCQ (Single Correct Answer)
+1
-0
A cylindrical conductor of diameter 0.1 mm carries a current of 90 mA . The current density ( in $\mathrm{Am}^{-2}$ ) is ( $\pi \approx 3$ )
A
$1.2 \times 10^7$
B
$3 \times 10^6$
C
$6 \times 10^6$
D
$2.4 \times 10^7$
4
KCET 2017
MCQ (Single Correct Answer)
+1
-0
Which of the following properties is 'False' for a bar magnet?
A
It doesn't produce magnetic field.
B
Its like poles repel and unlike poles attract.
C
Its poles cannot be separated.
D
It points in North-South direction when suspended.