An earth worm respires through skin and excretes through nephridia' Rewrite the above sentence beginning with 'A cockroach...... making appropriate changes

Heat from the sun reaches earth through vacuum.Name the mode of heat transfer in the above case

A voltmeter reads 80V when connected across the terminals of AC voltage source with frequency f = 100Hz : If the above voltage is connected across a (40 Omega) resistor find the current through the resistor. How will the current change if the same voltage is applied at 100kHz (1kHz = 1000 Hz)?