A charged particle enters in a strong perpendicular magnetic field. Then its kinetic energy
increases
decreases
remains constant
None of these
Calculate the current which will produce a deflection of 30° in a tangent galvanometer, if its reduction factor is 3 A.
1.732 A
0.732 A
3.732 A
2.732 A
What is shape of· magnet in moving coil galvanometer to make the radial magnetic field?
Concave
Horseshoe magnet
Convex
None of the above
A cyclotron can accelerate
β-particles
α-particles
high-velocity gamma rays
high-velocity X-rays
A galvanometer coil has a resistance of 15 Ω and gives full-scale deflection for a current of 4 mA. To convert it to an ammeter of range 0 to 6 A
10 mΩ resistance is to be connected in parallel to the galvanometer
10 mΩ resistance is to be connected in series with the galvanometer
0.1 Ω resistance is to be connected in parallel to the galvanometer
0.1 Ω resistance is to be connected in series with the galvanometer
A solenoid 1.5 m long and 0.4 cm in diameter possesses 10 turns/cm length. A current of 5 A falls through it. The magnetic field at the axis inside the solenoid is
2π × 10-3 T
2π × 10-5 T
4π × 10-2 T
4π × 10-3 T
A proton and a deuteron with the same initial kinetic energy enters a magnetic field in a direction perpendicular to the direction of the field. The ratio of the radii of the circular trajectories described by them is
1 : 4
1 : √2
1 : 1
1 : 2
A candidate connects a moving coil ammeter A and a moving coil voltmeter V and a resistance R as shown. If the voltmeter reads 20 V and the ammeter reads 4 A, then R is
equal to 5Ω
greater than 5Ω
less than 5Ω
none of these
Two identical galvanometers are taken, one is to be converted into an ammeter and other into a milliammeter. The shunt of milliammeter compared to ammeter is
less
more
zero
none of these
If the vibrations of a string are to be increased by a factor of two, the tension in the string should be made
twice
four times
eight times
half
B.
four times
The frequency of vibration of a string is given by
where l is the length, T the tension and m the mass per unit length.
Given, n1 = n, n2 = 2n
T2 = 4T1
Hence, to increase n by a factor of 2 tension must increase four times.