Electromagnetic Waves — Physics STD 12 Science — Question

Surface temperature of the sun is of the order of(a) 5000 K(b) 7000 K(c) 6000 K(d) 12000 K

The coil of the moving coil galvanometer is wound over an aluminium frame:

Gauss's law is true only if force due to a charge varies as

The colour of the positive column in a gas discharge tube depends on(a) The type of glass used to construct the tube(b) The gas in the tube (c) The applied voltage (d) The material of the cathode

A long, straight wire carries a current along the z-axis, One can find two points in the x−yplane such that:

The natural frequency of an LC - circuit is 1,25,000 cycles per second. Then the capacitor C is replaced by another capacitor with a dielectric medium of dielectric constant k. In this case, the frequency decreases by 25kHz. The value of k is:

The electrical conductivity of pure germanium can be increased by:

1. Increasing the temperature.
2. Doping acceptor impurities.
3. Doping donor impurities.
4. Irradiating ultraviolet light on it.

Which among the following cannot be the charge of a charged body?

In an oscillating system, a restoring force is a must. In an L-C circuit, the restoring force is provided by a/ an.

What is immaterial for an electric fuse wire (a) Specific resistance of the wire(b) Radius of the wire(c) Length of the wire(d) Current flowing through the wire