Physics Test 58

Two engines pass each other moving in opposite directions with uniform speed of 30 m/s. One of them is blowing a whistle of frequency 540 Hz. Calculate the frequency heard by driver of second engine before they pass each other. Speed of sound is 330 m/sec:

Three capacitors each of 4μF are to be connected in such a way that the effective capacitance is 6μF. This can be done by connecting them:

A magnetic dipole is acted upon by two magnetic fields which are inclined to each other at an angle of 75^∘. One of the fields has a magnitude of 15 mT. The dipole attains stable equilibrium at an angle of 30^∘ with this field. The  with this field. The magnitude of the other field (in mT) is close to

A 50Ω resistance is connected to a battery of 5 V. A galvanometer of resistance 100Ω is to be used as an ammeter to measure current through the resistance, for this a resistance rsrs is connected to the galvanometer.Which of the following connections should be employed if the measured current is within 1% of the current without the ammeter in the circuit?

Microwave oven acts on the principle of:

In Young’s double slit experiment, the distance between slits and the screen is 1.0 m and monochromatic light of 600 nm is being used. A person standing near the slits is looking at the fringe pattern. When the separation between the slits is varied, the interference pattern disappears for a particular distance d₀ between the slits. If the angular resolution of the eye is 1^∘ / 60, the value of d₀ is close to: