31.

Two simple harmonic motions are represented by the equation y₁ = 0.1  and y₂ = 0.1 cosπt. The phase difference of the velocity of particle 1 w.r.t. the velocity of the particle 2 is

• −π/6

• π/3

• −π/3

• −π/3

A heater coil is cut into two equal parts and only one part is now used in the heater. The heat generated will now be

• doubled

• four times

• one fourth

• one fourth

When two tuning forks (fork 1 and fork 2) are sounded simultaneously, 4 beats per second are heard. Now, some tape is attached on the prong of the fork 2. When the tuning forks are sounded again, 6 beats per seconds are heard. If the frequency of fork 1 is 200 Hz, then what was the original frequency of fork 2?

• 200 Hz

• 202 Hz

• 196 Hz

• 196 Hz

If a simple harmonic motion is represented by , its time period is its time period

• 2π/α

• 

• 2πα

• 2πα

The bob of a simple pendulum is a spherical hollow ball filled with water. A plugged hole near the bottom of the oscillation bob gets suddenly unplugged. During observation, till water is coming out, the time period of oscillation would

• first increase and then decrease to the original value.

• first decreased then increase to the original value.

• remain unchanged.

• remain unchanged.

An observer moves towards a stationary source of the sound, with a velocity one-fifth of the velocity of sound. What is the percentage increase in the apparent frequency?

• 0

• 0.5%

• 5%

• 5%

A moving coil galvanometer has 150 equal divisions. Its current sensitivity is 10 divisions per milliampere and voltage sensitivity is 2 divisions per millivolt. In order that each division reads 1 volt, the resistance in ohms needed to be connected in series with the coil will be

• 10³

• 10⁵

• 99995

• 99995

Two voltameters one of copper and another of silver, are joined in parallel. When a total charge q flows through the voltameters, equal amount of metals are deposited. If the electrochemical equivalents of copper and silver are z₁ and z₂ respectively the charge which flows through the silver voltameter is

In the circuit, the galvanometer G shows zero deflection. If the batteries A and B have negligible internal resistance, the value of the resistor R will be

• 200Ω

• 100Ω

• 500 Ω

• 500 Ω

A fully charged capacitor has a capacitance ‘C’ it is discharged through a small coil of resistance wire embedded in a thermally insulated block of specific heat capacity ‘s’ and mass ‘m’. If the temperature of the block is raised by ‘∆T’. The potential difference V across the capacitance