A battery of 6V and internal resistance 2 Ω is connected to a silver voltmeter. If the current of 1.5 A flows through the circuit, the resistance of the voltmeter is
4 Ω
2 Ω
6 Ω
1 Ω
In the given circuit below, the points A, B and C are at same potential. If the potential difference between B and D is 30 V, then the potential difference between A and O is
7.5 V
10 V
15 V
5 V
The ratio of resistances of two copper wires of the same length and of same cross-sectional area when connected in series to that when connected in parallel is
1 : 1
1 : 2
2 : 1
4 : 1
A flow of 106 electrons per second in a conducting wire constitutes a flow of current
1.6 × 10-15 A
1.6 × 10-11 A
1.6 × 10-13 A
1.6 × 10-19 A
Identify the wrong statement.
Current loop is equivalent to a magnetic dipole
Magnetic dipole moment of a planar loop of area A carrying current I is I2A
Particles like proton, electron carry an intrinsic magnetic moment
The current loop (magnetic moment m) placed in a uniform magnetic field, B experiences a torque ζ = m x B
A single turn circular coil is connected to a cell as shown in figure. Magnetic field at the centre O of the coil is
zero
A proton is travelling along the x-direction with velocity 5 x 106 ms-1.The magnitude of force experienced by the proton in a magnetic field tesla is
3.2 × 10-13 N
5.3 × 10-13 N
3.2 × 1013 N
6.3 × 10-13 N
A.
3.2 × 10-13 N
Given, B = tesla
and v = 5 × 106 ms-1
We know that,
Net force, F = q (v × B)
or F = qvB .
⇒ F = 1.6 × 10-19 × 5 × 106 × 0.4
∴ F = 3.2 × 10-13 N
The shunt required to send 10% of the main current through a moving coil galvanometer of resistance 99 Ω is
99 Ω
9.9 Ω
11 Ω
10 Ω
Two identical coils of 5 turns each carry 1 A and 2 A current respectively. Assume that they have common centre with their planes parallel to each other. If their radius is 1 m each and the direction of flow of current in the coils are in opposite directions, then the magnetic field produced on its axial line at a distance of m, from the common centre is (in tesla)
0
The ratio of the magnetic fields produced at the centre of a solenoid for a flow of current 1 A to that produced inside toroid for the flow of current 2 A both having same number of turns per unit length is
1 : 1
1 : 2
2 : 1
1 : 4