1
NEET 2019
MCQ (Single Correct Answer)
+4
-1
Change Language
In which of the following devices, the eddy current effect is not used?
A
magnetic braking in train
B
electromagnet
C
electric heater
D
induction furnace
2
NEET 2019
MCQ (Single Correct Answer)
+4
-1
Change Language
When a block of mass M is suspended by a long wire of length L, the length of the wire becomes (L + $$l$$). The elastic potential energy stored in the extended wire is :
A
Mgl
B
mgL
C
$${1 \over 2}$$Mgl
D
$${1 \over 2}$$MgL
3
NEET 2019
MCQ (Single Correct Answer)
+4
-1
Change Language
Two point charges A and B, having charges +Q and – Q respectively, are placed at certain distance apart and force acting between them is F. If 25% charge of A is transferred to B, then force between the charges becomes :
A
F
B
$${{16F} \over 9}$$
C
$${{9F} \over {16}}$$
D
$${{4F} \over 3}$$
4
NEET 2019
MCQ (Single Correct Answer)
+4
-1
Change Language
A parallel plate capacitor of capacitance 20 $$\mu $$F is being charged by a voltage source whose potential is changing at the rate of 3V/s. The conduction current through the connecting wires, and the displacement current through the plates of the capacitor, would be, respectively :
A
zero, zero
B
zero, 60 $$\mu $$A
C
60 $$\mu $$A, 60 $$\mu $$A
D
60 $$\mu $$A, zero